Coatings for enhancement of properties and performance of substrate articles and apparatus

ABSTRACT

Coatings applicable to a variety of substrate articles, structures, materials, and equipment are described. In various applications, the substrate includes metal surface susceptible to formation of oxide, nitride, fluoride, or chloride of such metal thereon, wherein the metal surface is configured to be contacted in use with gas, solid, or liquid that is reactive therewith to form a reaction product that is deleterious to the substrate article, structure, material, or equipment. The metal surface is coated with a protective coating preventing reaction of the coated surface with the reactive gas, and/or otherwise improving the electrical, chemical, thermal, or structural properties of the substrate article or equipment. Various methods of coating the metal surface are described, and for selecting the coating material that is utilized.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to International Application No.PCT/US2016/017910, filed Feb. 13, 2016, which in turn claims the benefitunder the provisions of 35 U.S.C. § 119 of the following U.S.provisional patent applications: U.S. Provisional Patent Application No.62/116,181 filed Feb. 13, 2015 in the names of Carlo Waldfried, et al.for “THIN FILM ATOMIC LAYER DEPOSITION COATINGS”; U.S. ProvisionalPatent Application No. 62/167,890 filed May 28, 2015 in the names ofBryan C. Hendrix, et al. for “COATINGS TO PREVENT TRANSPORT OF TRACEMETALS BY AL2CL6 VAPOR”; U.S. Provisional Patent Application No.62/188,333 filed Jul. 2, 2015 in the names of Bryan C. Hendrix, et al.for “COATINGS FOR ENHANCEMENT OF PROPERTIES AND PERFORMANCE OF SUBSTRATEARTICLES AND APPARATUS”; and U.S. Provisional Patent Application No.62/221,594 filed Sep. 21, 2015 in the names of Bryan C. Hendrix, et al.for “COATINGS FOR ENHANCEMENT OF PROPERTIES AND PERFORMANCE OF SUBSTRATEARTICLES AND APPARATUS”. The disclosures of such U.S. Provisional PatentApplication Nos. 62/116,181, 62/167,890, 62/188,333, and 62/221,594 arehereby incorporated herein by reference, in their respective entireties,for all purposes.

FIELD

The present disclosure generally relates to coatings applicable to avariety of substrate articles and equipment, e.g., in respect ofstructures and apparatus having surface that is susceptible to formationthereon of undesired oxide, nitride, fluoride, chloride, or other halidecontaminant species. In specific aspects, the disclosure relates tosemiconductor manufacturing equipment and methods of enhancing theperformance thereof, and more specifically relates to semiconductormanufacturing equipment susceptible to contamination and particledeposition associated with the presence of dialiminum hexachloride vaporin such equipment, and to compositions and methods for combating suchadverse contamination and particle deposition.

DESCRIPTION OF THE RELATED ART

In many fields of endeavor, structures, materials, and apparatus areencountered that include surface susceptible to formation of contaminantspecies, such as surfaces of aluminum, anodized aluminum, quartz,stainless steel, etc. that are susceptible to formation of undesiredoxide, nitride, and halide (e.g., fluoride and/or chloride) contaminantspecies thereon, which interfere with the use, utility, or function ofthe associated products, equipment, or materials.

In the field of semiconductor manufacturing, aluminum andaluminum-containing materials are widely employed. Although aluminum asa metallization material has been significantly displaced by copper innanoscale integrated circuitry applications, aluminum nonethelesscontinues to be extensively utilized as a wire bonding and connectionmaterial, as well as use in thin film materials, e.g., AlN thin films asbarrier layers, piezoelectric device components, cold cathode materials,etc., as well as in compound semiconductor compositions for applicationssuch as LEDs and other optoelectronic devices or Al₂O₃ layers asdielectrics, dielectric dopants, barriers, optical coatings, etc.

In many of such applications, halogen gases are employed insemiconductor manufacturing equipment for processing of films in thedevice manufacturing operation, or as co-flow cleaning agents forremoval of accumulated contaminant deposits on surfaces and componentsof the semiconductor manufacturing equipment. These halogen gases mayinclude chloro species, which can reactively form dialuminumhexachloride (Al₂Cl₆) vapor when contacting aluminum present in theequipment, e.g., on wafers, or on surfaces or components of theequipment. Such dialuminum hexachloride vapor may in turn attackstainless steel surfaces and components in the semiconductormanufacturing equipment and serve to transport measurable levels ofmetals such as chromium, iron, and nickel to the wafers undergoingprocessing.

Another class of applications uses Al₂Cl₆ vapor to deposit aluminumcontaining films. Although Al₂O₃ is widely deposited by ALD usingtrimethyl aluminum as a source reagent, trimethyl aluminum nonethelessis a pyrophoric liquid subject to significant safety and regulatorycosts. Al₂Cl₆ vapor can be readily produced above solid AlCl₃ in a solidvaporizer, such as solid vaporizer units of the type commercially soldunder the trademark ProE-Vap by Entegris, Inc., Billerica, Mass., USA.

Stainless steel components of semiconductor and manufacturing equipmentmay be formed of 316 stainless steel or other stainless steel alloysthat are generally electropolished. Such electropolishing generallyleaves the surface coated with a layer of passive oxide containingchromium, iron, nickel, and other alloy components. In addition, suchmetal components may form surface traces of corresponding oxides bynative oxidation processes. As a result, when dialuminum hexachlorideencounters such metal oxides, the metal oxides react with the dialuminumhexachloride to form corresponding vapor phase metalloaluminum chloridecompounds which can transport to wafers and semiconductor devices ordevice precursor structures and may deposit the trace metals orotherwise damage the products being manufactured in the equipment.Alternatively, the metal oxide can react with Al₂Cl₆ vapor to form Al₂O₃and particulate metal chlorides that can transport to the devicestructure and cause damage. Additionally, AlCl₃ solid can contact themetal oxide surface to form either vapor metalloaluminum chloride orsolid chloride particles.

In consequence, it would be a significant improvement to suppress thedeleterious interaction of dialuminum hexachloride with metal surfacesand components in such semiconductor manufacturing equipment and otherthin film deposition or etching equipment.

There is also an ongoing need for coatings for a variety of industrialapplications that are dense, pinhole-free and defect-free, and provideother coating qualities and advantages, such as electrical insulation ofparts, the ability to coat parts conformally, chemical and etchresistance, corrosion resistance, diffusion barrier properties, andadhesion layer properties.

SUMMARY

The present disclosure generally relates to coatings applicable to avariety of substrate articles, structures, materials, and equipment, andrelates in specific aspects to semiconductor manufacturing equipment andmethods of enhancing the performance thereof, and more specifically tosemiconductor manufacturing equipment susceptible to contamination andparticle deposition associated with the presence of dialuminumhexachloride in such equipment, and to compositions and methods forcombating such adverse contamination and particle deposition.

The disclosure relates in one aspect to a structure, material, orapparatus comprising metal surface susceptible to formation of oxide,nitride, or halide of said metal thereon, the metal surface configuredto be contacted in use or operation of said structure, material, orapparatus with gas, solid, or liquid that is reactive with such metaloxide, nitride, or halide, to form a reaction product that isdeleterious to said structure, material, or apparatus and its use oroperation, wherein the metal surface is coated with a protective coatingpreventing reaction of the coated surface with the reactive gas.

In one aspect, the disclosure relates to a semiconductor manufacturingapparatus comprising metal surface susceptible to formation of oxide,nitride, or halide of said metal thereon, the metal surface configuredto be contacted in operation of said apparatus with gas, solid, orliquid that is reactive with said metal oxide, nitride, or halide toform a reaction product, e.g., a particulate reaction product and/or avapor reaction product, that is deleterious to said apparatus and itsoperation, wherein the metal surface is coated with a protective coatingpreventing reaction of the coated surface with the reactive gas.

A further aspect of the disclosure relates to a method of improvingperformance of a structure, material, or apparatus comprising metalsurface susceptible to formation of oxide, nitride, or halide of saidmetal thereon, wherein the metal surface is configured to be contactedin use or operation of said structure, material, or apparatus with gas,solid, or liquid that is reactive with said metal oxide, nitride, orhalide to form a reaction product that is deleterious to said structure,material, or apparatus and its use or operation, said method comprisingcoating the metal surface with a protective coating preventing reactionof the coated surface with the reactive gas.

In another aspect, the disclosure relates to a method of improvingperformance of a semiconductor manufacturing apparatus comprising metalsurface susceptible to formation of oxide, nitride, or halide of saidmetal thereon, wherein the metal surface is configured to be contactedin operation of said apparatus with gas, solid, or liquid that isreactive with the metal oxide, nitride, or halide to form a reactionproduct that is deleterious to said apparatus and its operation, suchmethod comprising coating the metal surface with a protective coatingpreventing reaction of the coated surface with the reactive gas.

In another aspect, the disclosure relates to improving the performanceof a semiconductor manufacturing apparatus in contact with a reactivesolid.

In accordance with a further aspect of the disclosure, there areprovided thin film atomic layer deposition coatings for industrialapplications. Thin film coatings in accordance with the disclosure aredescribed in the specification herein.

Another aspect of the disclosure relates to a composite ALD coating,comprising layers of different ALD product materials.

A further aspect of the disclosure relates to a composite coating,comprising at least one ALD layer and at least one deposited layer thatis not an ALD layer.

In another aspect, the disclosure relates to a method of forming apatterned ALD coating on a substrate, comprising forming a pattern onthe substrate of a layer of surface termination material that iseffective to prevent ALD film growth.

In another aspect, the disclosure relates to a method of filling and/orsealing surface infirmities of a material, said method comprisingapplying an ALD coating on a surface infirmity of the material, at athickness effecting filling and/or sealing of the infirmity.

A further aspect of the disclosure relates to a filter, comprising amatrix of fibers and/or particles, the fibers and/or particles beingformed of metal and/or polymeric material, wherein the matrix of fibersand/or particles has an ALD coating thereon, wherein the ALD coatingdoes not alter pore volume of the matrix of fibers and/or particles bymore than 5%, as compared to a corresponding matrix of fibers and/orparticles lacking said ALD coating thereon, and wherein when the fibersand/or particles are formed of metal, and the ALD coating comprisesmetal, the metal of the ALD coating is different from the metal of thefibers and/or particles.

Yet another aspect of the disclosure relates to a method of delivering agaseous or vapor stream to a semiconductor processing tool, said methodcomprising providing a flow path for the gaseous or vapor stream, from asource of said gaseous or vapor stream to the semiconductor processingtool, and flowing the gaseous or vapor stream through a filter in theflow path to remove extraneous solid material from the stream, whereinthe filter comprises a filter of the present disclosure, as variouslydescribed herein.

The disclosure in a further aspect relates to a filter comprising asintered matrix of stainless steel fibers and/or particles that iscoated with an ALD coating of alumina, wherein the sintered matrixcomprises pores of a diameter in a range of from 1 to 40 μm, e.g., from10 to 20 μm, and the ALD coating has a thickness in a range of from 2 to500 nm.

Another aspect of the disclosure relates to a solid vaporizer apparatuscomprising a vessel defining an interior volume including supportsurface therein for solid material to be vaporized, wherein at least aportion of the support surface has an ALD coating thereon.

The disclosure relates in a further aspect to a thin film coatingcomprised of one or more layers, wherein at least one layer is depositedby atomic layer deposition.

Another aspect of the disclosure relates to an ALD coating having a filmthickness exceeding 1000 Å.

A further aspect of the disclosure relates to an ALD coating comprisinga very dense, pinhole free, defect-free layer.

Yet another aspect of the disclosure relates to a thin film coatingdeposited on a part surface other than an integrated circuit device on asilicon wafer.

In a further aspect, the disclosure relates to an ALD coating comprisedof insulating metal oxide and metal.

Another aspect the disclosure relates to an ALD coating that isdepositable at temperature in a range of from 20° C. to 400° C.

A further aspect of the disclosure relates to an ALD coating comprisinga single film having a defined stoichiometry.

Another aspect of the disclosure relates to a thin film coatingcomprising an ALD layer in combination with at least one other layerdeposited by a different deposition technique.

In another aspect the disclosure relates to a multilayer ALD coating,having a coating thickness not exceeding 2 μm.

Another aspect of the disclosure relates to an ALD coating of materialselected from the group consisting of oxides, alumina, aluminum-oxynitride, yttria, yttria-alumina mixes, silicon oxide, siliconoxy-nitride, transition metal oxides, transition metal oxy-nitrides,rare earth metal oxides, and rare earth metal oxy-nitrides.

A further aspect of the disclosure relates to a method of forming apatterned ALD coating on a substrate part, such method comprising:uniformly coating the part with an ALD coating, and etching backunwanted coating material through a mask.

Another method aspect of the disclosure relates to a method of forming apatterned ALD coating on a substrate part, such method comprising:masking an area of the part; coating the part with an ALD coating; andremoving the ALD coating from the mask area of the part.

A still further method aspect of the disclosure relates to a method offorming a patterned ALD coating on a substrate part, such methodcomprising: patterning the substrate part with material comprising asurface termination component that blocks the ALD film growth; andcoating the patterned substrate part with an ALD coating.

A further aspect of the disclosure relates to a method of electricallyinsulating a substrate part, comprising applying to said substrate parta defect-free, pin-hole-free, dense, electrically insulating ALDcoating.

The disclosure relates in another aspect to a coating on a substratesurface, comprising an ALD coating having a chemically resistant andetch-resistant character.

Another aspect of the disclosure relates to a coating on a substratesurface, comprising an ALD corrosion-resistant coating.

A further aspect of the disclosure relates to a coating on a substratesurface, comprising an ALD diffusion barrier layer.

A still further aspect of the disclosure relates to a coating on asubstrate surface, comprising an ALD adhesion layer.

Yet another aspect of the disclosure relates to a coating on a substratesurface, comprising an ALD surface sealant layer.

In another aspect, the disclosure relates to a porous filter comprisinga fibrous metal membrane coated with a chemically resistant ALD coating.

A further aspect of the disclosure relates to a filter comprising aporous material matrix coated with an ALD coating wherein the averagepore size of the porous metal matrix has been reduced by the ALDcoating, in relation to a corresponding porous material matrix notcoated with the ALD coating.

Another aspect of the disclosure relates to a filter comprising a porousmaterial matrix coated with an ALD coating, wherein the coatingthickness is directionally varied to provide a corresponding pore sizegradient in the filter.

In a further aspect, the disclosure relates to a method of fabricating aporous filter, comprising coating a porous material matrix with an ALDcoating, to reduce average pore size of the porous material matrix.

In another aspect, the disclosure relates to a solid vaporizer apparatuscomprising a container defining therein an interior volume, an outletconfigured to discharge precursor vapor from the container, and supportstructure in the interior volume of the container adapted to supportsolid precursor material thereon for volatilization thereof to form theprecursor vapor, wherein the solid precursor material comprises aluminumprecursor, and wherein at least part of surface area in the interiorvolume is coated with an alumina coating.

A further aspect the disclosure relates to a method of enhancingcorrosion resistance of a stainless steel structure, material, orapparatus that in use or operation is exposed to aluminum halide, saidmethod comprising coating said stainless steel structure, material, orapparatus with an alumina coating.

Another aspect of the disclosure relates to a semiconductor processingetching structure, component, or apparatus that in use or operation isexposed to etching media, said structure, component, or apparatus beingcoated with a coating comprising a layer of yttria, wherein the layer ofyttria optionally overlies a layer of alumina in said coating.

Yet another aspect of the disclosure relates to a method of enhancingcorrosion resistance and etch resistance of a semiconductor processingetching structure, component, or apparatus that in use or operation isexposed to etching media, said method comprising coating the structure,component, or apparatus with a coating comprising a layer of yttria,wherein the layer of yttria optionally overlies a layer of alumina insaid coating.

Another aspect, the disclosure relates to a etch chamber diffuser platecomprising a nickel membrane encapsulated with an alumina coating.

A further aspect of the disclosure relates to a method of enhancingcorrosion resistance and etch resistance to an etch chamber diffuserplate comprising a nickel membrane, comprising coating the nickelmembrane with an encapsulating coating of alumina.

In another aspect, the disclosure relates to a vapor depositionprocessing structure. component, or apparatus that in use or operationis exposed to halide media, said structure, component, or apparatusbeing coated with a coating of yttria comprising an ALD base coating ofyttria, and a PVD over coating of yttria.

In still another aspect, the disclosure relates to a method of enhancingcorrosion resistance and etch resistance of a vapor depositionprocessing structure, component, or apparatus that in use or operationis exposed to halide media, said method comprising coating thestructure, component, or apparatus with a coating of yttria comprisingan ALD base coating of yttria, and a PVD over coating of yttria.

Yet another aspect of the disclosure relates to a quartz envelopestructure coated on an interior surface thereof with an aluminadiffusion barrier layer.

A further aspect of the disclosure relates to a method of reducingdiffusion of mercury into a quartz envelope structure susceptible tosuch diffusion in operation thereof, said method comprising coating aninterior surface of the quartz envelope structure with an aluminadiffusion barrier layer.

A still further aspect of the disclosure relates to a plasma sourcestructure, component, or apparatus that in use or operation is exposedto plasma and voltage exceeding 1000 V, wherein plasma-wetted surface ofsaid structure, component or apparatus is coated with an ALD coating ofalumina, and said alumina coating is overcoated with a PVD coating ofaluminum oxynitride.

The disclosure in one aspect relates to a method of enhancing servicelife of a plasma source structure, component, or apparatus that in useor operation is exposed to plasma and voltage exceeding 1000 V, saidmethod comprising coating plasma-wetted surface of said structure,component or apparatus with an ALD coating of alumina, and over coatingsaid alumina coating with a PVD coating of aluminum oxynitride.

The disclosure in another aspect relates to a dielectric stack,comprising sequential layers including a base layer of alumina, a nickelelectrode layer thereon, an ALD alumina electrical stand-off layer onthe nickel electrode layer, a PVD aluminum oxynitride thermal expansionbuffer layer on the ALD alumina electrical stand-off layer, and a CVDsilicon oxynitride wafer contact surface and electrical spacer layer onthe PVD aluminum oxynitride thermal expansion buffer layer.

The disclosure in another aspect relates to a plasma activationstructure, component, or apparatus, comprising aluminum surface coatedwith one of the multilayer coatings of (i) and (ii): (i) a base coat ofCVD silicon on the aluminum surface, and a layer of ALD zirconia on thebase coat of CVD silicon; and (ii) a base coat of CVD silicon oxynitrideon the aluminum surface, and a layer of ALD alumina on the base coat ofCVD silicon oxynitride.

Another aspect of the disclosure relates to a method of reducingparticle formation and metal contamination for an aluminum surface of aplasma activation structure, component or apparatus, said methodcomprising coating the aluminum surface with one of the multilayercoatings of (i) and (ii): (i) a base coat of CVD silicon on the aluminumsurface, and a layer of ALD zirconia on the base coat of CVD silicon;and (ii) a base coat of CVD silicon oxynitride on the aluminum surface,and a layer of ALD alumina on the base coat of CVD silicon oxynitride.

A porous matrix filter is contemplated in another aspect of thedisclosure, the porous matrix filter comprising a membrane formed ofstainless steel, nickel, or titanium, wherein the membrane isencapsulated with alumina to a coating penetration depth in a range offrom 20 to 2000 μm.

In a corresponding method aspect the disclosure relates to a method ofmaking a porous matrix filter comprising encapsulating a membrane formedof stainless steel, nickel, or titanium with alumina to a coatingpenetration depth in a range of from 20 to 2000 μm.

Other aspects, features and embodiments of the disclosure will be morefully apparent from the ensuing description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a deposition furnace of asemiconductor wafer processing tool according to one aspect of thepresent disclosure.

FIG. 2 is a schematic representation of a deposition furnace processsystem according to another aspect of the disclosure, for coating wafersusing Al₂Cl₆ vapor, utilizing a solid source delivery vaporizer in theform of an ampoule for vaporizing AlCl₃ to form the Al₂Cl₆ vapor,wherein the trays and internal surfaces of the ampoule are coated withAl₂O₃, as well as all of the valves, tubing and filters downstream ofthe ampoule being coated with Al₂O₃.

FIG. 3 is a perspective, partial breakaway view of a vaporizer containerhaving holders to help promote contact of a gas with vapor from materialsupported by the holders.

FIG. 4 is a micrograph, at 15K magnification, of the surface of a porousmetal frit of a type usefully employed in filter elements, according toanother aspect of the disclosure.

FIG. 5 is a micrograph, at 20,000 times magnification, of the surface ofelectropolished 316 L stainless steel having no exposure to AlCl₃.

FIG. 6 is a micrograph, at 1000 times magnification, of a surface ofelectropolished 316 L stainless steel after exposure to AlCl₃ for 10days at 120° C. in an anhydrous environment.

FIG. 7 is a micrograph, at 50,000 times magnification, of across-section of electropolished 316 L stainless steel that did not haveany exposure to AlCl₃.

FIG. 8 is a micrograph, at 20,000 times magnification, of uncoated 316 Lstainless steel after 10 days of exposure to AlCl₃ at 120° C. in ananhydrous environment.

FIG. 9 is a micrograph, at 35,000 times magnification, ofelectropolished 316 L stainless steel after 10 days of exposure to AlCl₃at 120° C. in an anhydrous environment, showing multiple pits along thesurface.

FIG. 10 is a micrograph, at 35,000 times magnification, ofelectropolished 316 L stainless steel coated by 100 ALD cycles of Al₂O₃using trimethyl aluminum and water, prior to exposure to anhydrous AlCl₃at 120° C. for 10 days.

FIG. 11 is a micrograph, at 35,000 times magnification, ofelectropolished 316 L stainless steel coated by 1000 ALD cycles of Al₂O₃using trimethyl aluminum and water, prior to exposure to anhydrous AlCl₃at 120° C. for 10 days.

FIG. 12 is a composite photograph of sample stainless steel coupons, ofwhich sample coupons 2 and 3 were coated with a 470 Å thick coating ofalumina, and sample coupons 12 and 13 were uncoated, has photographedafter nine days exposure to AlCl₃ at 155° C.

FIG. 13 is a top-down scanning electron microscope (SEM) micrograph ofan alumina-coated stainless steel sample after exposure to WCl₅ at 220°C. for 10 days.

FIG. 14 is a focused ion beam (FIB) cross-section of the edge of thecoating in the sample of FIG. 13 after exposure to WCl₅ at 220° C. for10 days.

FIG. 15 is a perspective view of a stainless steel holder usefullyemployed in a vaporizer ampoule for aluminum trichloride (AlCl₃) solidprecursor delivery for an aluminum process, in which the aluminumtrichloride precursor is supported by the holder and volatilized to Formaluminum trichloride precursor vapor for discharge from the vaporizerampoule and transport through associated flow circuitry to the aluminumprocess.

FIG. 16 is a perspective view of a stainless steel holder of the typeshown in FIG. 15, as coated by atomic layer deposition with a coating ofalumina thereon, so that the stainless steel surface is encapsulated bythe alumina coating in the corrosive environment involving aluminumtrichloride (AlCl₃) exposure to which the holder is subjected in use andoperation of the vaporizer ampoule.

FIG. 17 is a schematic elevation view of an alumina coating applied byatomic layer deposition to a stainless steel substrate, to providecorrosion resistance, prevent chemical reaction with the substrate, andreduce metals contamination in use.

FIG. 18 shows channels of a plasma etch apparatus coated with yttria(Y₂O₃).

FIG. 19 is a schematic elevation view of an yttria coating applied byatomic layer deposition over alumina.

FIG. 20 is a photograph of a diffuser plate assembly, including astainless steel frame and a nickel filter membrane, as coated with analumina coating.

FIG. 21 is a schematic elevation view of the diffuser plate assembly, inwhich the stainless steel frame and nickel membrane are encapsulatedwith ALD alumina.

FIG. 22 is a schematic elevation view of a coating structure, includingan aluminum substrate, an ALD coating of alumina, and a PVD coating ofAlON.

FIG. 23 is a schematic elevation view of the layer structure of adielectric stack useful for hot chuck components, in which an aluminasubstrate has an electrode metal thereon, on which is an electricalstand-off layer of ALD alumina, on which is a PVD coating of aluminumoxynitride, on which is a layer of chemical vapor deposition (CVD)deposited silicon oxynitride (SiON).

FIG. 24 is a schematic elevation view of a multilayer stack including achemical vapor deposition-applied layer of silicon on an aluminumsubstrate, with an ALD layer of zirconia on the CVD Si layer.

FIG. 25 is a schematic elevation view of a multilayer stack including aCVD layer of silicon oxynitride on an aluminum substrate, and an ALDlayer of alumina on the CVD SiON coating layer.

FIG. 26 is a micrograph of porous material having a 1.5 mm wallthickness and pore size of 2-4 μm, coated with alumina by atomic layerdeposition.

FIG. 27 is a schematic representation of an encapsulated membrane,comprising a membrane formed of stainless steel, nickel, titanium, orother suitable material, which has been fully encapsulated with aluminadeposited by ALD.

FIG. 28 is a photomicrograph of a coated filter, wherein the coating isalumina, having a coating penetration depth of 35 μm.

FIG. 29 is a photomicrograph of a coated filter, wherein the coating isalumina, having a coating penetration depth of 175 μm

DETAILED DESCRIPTION

The present disclosure generally relates to coatings applicable to avariety of substrate articles, materials, structures, and equipment. Invarious aspects, the disclosure relates to semiconductor manufacturingequipment and methods of enhancing the performance thereof, and morespecifically to semiconductor manufacturing equipment susceptible tocontamination and particle deposition associated with the presence ofdialuminum hexachloride in such equipment, and to compositions andmethods for combating such adverse contamination and particledeposition.

As used herein, the identification of a carbon number range, e.g., inC₁-C₁₂ alkyl, is intended to include each of the component carbon numbermoieties within such range, so that each intervening carbon number andany other stated or intervening carbon number value in that statedrange, is encompassed, it being further understood that sub-ranges ofcarbon number within specified carbon number ranges may independently beincluded in smaller carbon number ranges, within the scope of theinvention, and that ranges of carbon numbers specifically excluding acarbon number or numbers are included in the invention, and sub-rangesexcluding either or both of carbon number limits of specified ranges arealso included in the invention. Accordingly, C₁-C₁₂ alkyl is intended toinclude methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl and dodecyl, including straight chain as well asbranched groups of such types. It therefore is to be appreciated thatidentification of a carbon number range, e.g., C₁-C₁₂, as broadlyapplicable to a substituent moiety, enables, in specific embodiments ofthe invention, the carbon number range to be further restricted, as asub-group of moieties having a carbon number range within the broaderspecification of the substituent moiety. By way of example, the carbonnumber range e.g., C₁-C₁₂ alkyl, may be more restrictively specified, inparticular embodiments of the invention, to encompass sub-ranges such asC₁-C₄ alkyl, C₂-C₈ alkyl, C₂-C₄ alkyl, C₃-C₅ alkyl, or any othersub-range within the broad carbon number range. In other words, a carbonnumber range is deemed to affirmatively set forth each of the carbonnumber species in the range, as to the substituent, moiety, or compoundto which such range applies, as a selection group from which specificones of the members of the selection group may be selected, either as asequential carbon number sub-range, or as specific carbon number specieswithin such selection group.

The same construction and selection flexibility is applicable tostoichiometric coefficients and numerical values specifying the numberof atoms, functional groups, ions or moieties, as to specified ranges,numerical value constraints (e.g., inequalities, greater than, less thanconstraints), as well as oxidation states and other variablesdeterminative of the specific form, charge state, and compositionapplicable to dopant sources, implantation species, and chemicalentities within the broad scope of the present disclosure.

“Alkyls” as used herein include, but are not limited to, methyl, ethyl,propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl and isopentyl and thelike. “Aryls” as used herein includes hydrocarbons derived from benzeneor a benzene derivative that are unsaturated aromatic carbocyclic groupsof from 6 to 10 carbon atoms. The aryls may have a single or multiplerings. The term “aryl” as used herein also includes substituted aryls.Examples include, but are not limited to phenyl, naphthyl, xylene,phenylethane, substituted phenyl, substituted naphthyl, substitutedxylene, substituted phenylethane and the like. “Cycloalkyls” as usedherein include, but are not limited to cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and the like. In all chemical formulae herein, arange of carbon numbers will be regarded as specifying a sequence ofconsecutive alternative carbon-containing moieties, including allmoieties containing numbers of carbon atoms intermediate the endpointvalues of carbon number in the specific range as well as moietiescontaining numbers of carbon atoms equal to an endpoint value of thespecific range, e.g., C₁-C₆, is inclusive of C₁, C₂, C₃, C₄, C₅ and C₆,and each of such broader ranges may be further limitingly specified withreference to carbon numbers within such ranges, as sub-ranges thereof.Thus, for example, the range C₁-C₆ would be inclusive of and can befurther limited by specification of sub-ranges such as C₁-C₃, C₁-C₄,C₂-C₆, C₄-C₆, etc. within the scope of the broader range.

The disclosure relates in one aspect to a structure, material, orapparatus comprising metal surface susceptible to formation of oxide,nitride, or halide (fluoride, chloride, iodide, and/or bromide) of suchmetal thereon, the metal surface configured to be contacted in use oroperation of such structure, material, or apparatus with gas, solid, orliquid that is reactive with said metal oxide, nitride, or halide toform a reaction product that is deleterious to the structure, material,or apparatus and its use or operation, wherein the metal surface iscoated with a protective coating preventing reaction of the coatedsurface with the reactive gas.

In one aspect, the disclosure relates to a semiconductor manufacturingapparatus comprising metal surface susceptible to formation of oxide,nitride, or halide of said metal thereon, the metal surface configuredto be contacted in use or operation of said apparatus with gas, solid,or liquid that is reactive with said metal to form a reaction productthat is deleterious to said apparatus and its use or operation, whereinthe metal surface is coated with a protective coating preventingreaction of the coated surface with the reactive gas.

In such semiconductor manufacturing apparatus, the metal oxide may invarious embodiments comprise at least one oxide of one or more of Cr,Fe, Co, and Ni, or in other embodiments the metal oxide may comprise atleast one oxide of one or more of Cr, Fe, and Ni. Metal nitrides may forexample form from iron or cobalt in the presence of ammonia duringprocessing when ammonia is present, with the resulting iron nitride orcobalt nitride subsequently reacting with AlCl₃ or TiCl₄. Metal halidesmay form on the metal surface during and etch operation or a cleaningcycle operation. The metal surface in various embodiments may comprisestainless steel surface. In specific embodiments, the gas that isreactive with the metal oxide, nitride, or halide to form a reactionproduct that is deleterious to the apparatus and its use or operation,comprises Al₂Cl₆.

The protective coating in specific applications may comprise one or moreof coating materials selected from the group consisting of Al₂O₃, oxidesof the formula MO, wherein M is Ca, Mg, or Be; oxides of the formulaM′O₂, wherein M′ is a stoichiometrically acceptable metal; and oxides ofthe formula Ln₂O₃, wherein Ln is a lanthanide element, e.g., La, Sc, orY. More generally, the protective coating may comprise a metal oxide forwhich the free energy of reaction with the material that is contactedwith the metal surface in the operation of the apparatus, is greaterthan or equal to zero.

A further aspect of the disclosure relates to a method of improvingperformance of a structure, material, or apparatus comprising metalsurface susceptible to formation of oxide, nitride, or halide of suchmetal thereon, wherein the metal surface is configured to be contactedin use or operation of said structure, material, or apparatus with gas,solid, or liquid that is reactive with said metal oxide, nitride, orhalide to form a reaction product that is deleterious to said structure,material, or apparatus and its use or operation, such method comprisingcoating the metal surface with a protective coating preventing reactionof the coated surface with the reactive gas.

In another aspect, the disclosure relates to a method of improvingperformance of a semiconductor manufacturing apparatus comprising metalsurface susceptible to formation of oxide, nitride, or halide of saidmetal thereon, wherein the metal surface is configured to be contactedin use or operation of said apparatus with gas that is reactive withsuch metal oxide, nitride, or halide to form a reaction product that isdeleterious to said apparatus and its use or operation, such methodcomprising coating the metal surface with a protective coatingpreventing reaction of the coated surface with the reactive gas.

The metal oxide, nitride, or halide in various embodiments may compriseat least one oxide, nitride, or halide of one or more of Cr, Fe, Co, andNi, and may comprise in other embodiments at least one oxide, nitride,or halide of one or more of Cr, Fe, and Ni, or any other suitable metaloxide, nitride, or halide species. The metal surface may for examplecomprise stainless steel. The gas that is reactive with the metal oxide,nitride, or halide to form a reaction product that is deleterious to thestructure, material, or apparatus and its use or operation, may compriseAl₂Cl₆.

The protective coating that is applied to the metal surface in theaforementioned method may comprise one or more of coating materialsselected from the group consisting of Al₂O₃, oxides of the formula MO,wherein M is Ca, Mg, or Be; oxides of the formula M′O₂, wherein M′ is astoichiometrically acceptable metal; and oxides of the formula Ln₂O₃,wherein Ln is a lanthanide element, e.g., La, Sc, or Y. More generally,the protective coating may comprise a metal oxide for which the freeenergy of reaction with the gas that is contacted with the metal surfacein the use or operation of said structure, material, or apparatus, isgreater than or equal to zero.

The protective coating may be applied to the metal surface in the methodof the present disclosure by any suitable technique, and in specificapplications, the coating operation may comprise physical vapordeposition (PVD), chemical vapor deposition (CVD), solution deposition,or atomic layer deposition (ALD) of the protective coating.

ALD is a preferred technique for application of the protective coatingto the metal surface. In specific applications, plasma-enhanced ALD maybe utilized as the ALD process for forming the protective coating on themetal surface. In various ALD embodiments, the protective coating maycomprise Al₂O₃. Such protective coating may for example be applied byatomic layer deposition comprising a process sequence in whichtrimethylaluminum and ozone are utilized in a cyclic ALD process to formthe protective coating, or alternatively, by atomic layer depositioncomprising a process sequence in which trimethylaluminum and water areutilized in a cyclic ALD process to form the protective coating.

In other ALD implementations of the method, the protective coating maycomprise a metal oxide of the formula MO, wherein M is Ca, Mg, or Be.For its application, the atomic layer deposition may comprise a processsequence in which a cyclopentadienyl M compound and ozone are utilizedin a cyclic ALD process to form the protective coating, or a processsequence in which a cyclopentadienyl M compound and water are utilizedin a cyclic ALD process to form the protective coating, or a processsequence in which an M beta-diketonate compound and ozone are utilizedin a cyclic ALD process to form the protective coating, or othersuitable process sequence and metal oxide precursor compound. A widevariety of precursor ligands may be employed for deposition of theprotective coating, including, without limitation, H, C₁-C₁₀ alkyl,linear, branched, or cyclic, saturated or unsaturated; aromatic,heterocyclic, alkoxy, cycloalkyl, silyl, silylalkyl, silylamide,trimethylsilyl silyl-substituted alkyl, trialkylsilyl-substitutedalkynes, and trialkylsilylamido-substituted alkynes, dialkylamide,ethylene, acetylene, alkynes, substituted alkenes, substituted alkynes,diene, cyclopentadienyls alkenes, amines, alkyl amines or bidentateamines, ammonia, RNH₂ (wherein R is an organo, e.g., hydrocarbyl,substituent), amidinates, guanidinates, diazadiene cyclopentadienyls,oximes, hydroxyamines, acetates, beta-diketonates, beta-ketoiminates,nitriles, nitrates, sulfates, phosphates, halo; hydroxyl, substitutedhydroxyl, and combinations and derivatives thereof.

In still other ALD implementations of the method of applying theprotective coating to the metal surface, the protective coating maycomprise a metal oxide of the formula Ln₂O₃, wherein Ln is a lanthanideclement. Ln may for example be La, Sc, or Y. In applying the lanthanideoxide protective coating, the atomic layer deposition may comprise aprocess sequence in which a cyclopentadienyl Ln compound and ozone areutilized in a cyclic ALD process to form the protective coating, or aprocess sequence in which a cyclopentadienyl Ln compound and water areutilized in a cyclic ALD process to form the protective coating, or aprocess sequence in which an Ln beta-diketonate compound and ozone areutilized in a cyclic ALD process to form the protective coating, orother suitable process sequence and lanthanide precursor compound.

The protective coating may be coated on the metal surface at anysuitable thickness, e.g., a coating thickness in a range of from 5 nm to5 μm.

In various embodiments, the metal surface may be at temperature in arange of from 25° C. to 400° C. during coating of the metal surface withthe protective coating. In other embodiments, such metal surface may beat temperature in a range of from 150° C. to 350° C. during the coatingoperation. In still other embodiments, the temperature of the metalsurface may be in other ranges, for application of protective coatingthereto.

The problem addressed by the present disclosure of chemical attack andtransport of contaminant species in semiconductor manufacturingoperations, is particularly acute in stainless steel furnaces in whichwafers are processed for manufacture of microelectronic devices andother semiconductor manufacturing products. In such furnaces, the flowof dialuminum hexachloride vapor has been found to transport measurablelevels of Cr, Fe, and Ni to wafers when Al₂Cl₆ vapor is moved throughthe system. Current levels measured are consistent with the removal ofcorresponding oxides of such metals that are left on the surface of thestainless steel, e.g., 316L stainless steel, by either native oxidationor by electro-polishing.

The present disclosure addresses this problem by coating surfaces andcomponents of the furnace with a coating of a material that will notreact with Al₂Cl₆. This achieves a solution that is far preferable toapproaches for removing surface oxides, nitrides, and halides fromstainless steel surfaces and components so that they do not react withAl₂Cl₆, since there will always be low levels of ambient moistureleakage or maintenance events that will expose such surfaces andcomponents to moisture and oxygen, nitrogen, and halogens. Further, ifAl₂Cl₆ were to be flowed in large volumes through the furnace toreactively remove the metal oxides, nitrides, and halides, such approachwould severely degrade tool throughput and is not a viable solution.

The present disclosure contrariwise employs a coating of the surfacesand components in the furnace or other semiconductor manufacturingequipment, so that the surfaces and components are passivated and do notreact with the Al₂Cl₆. As discussed, the coating advantageouslycomprises one or more of coating materials selected from the groupconsisting of: Al₂O₃, oxides of the formula MO, wherein M is Ca, Mg, orBe; oxides of the formula M′O₂, wherein M′ is a stoichiometricallyacceptable metal, and oxides of the formula Ln₂O₃, wherein Ln is alanthanide element, e.g., La, Sc, or Y.

The coating can be applied in any suitable manner that produces acontinuous conformal coating on the surfaces and components of thesemiconductor manufacturing equipment, including techniques of physicalvapor deposition (PVD), chemical vapor deposition (CVD), solutiondeposition, and atomic layer deposition (ALD)

ALD deposition is particularly advantageous for coating filter elementsand the inside of tubes. Trimethylaluminum/ozone (TMA/O₃) ortrimethylaluminum/water (TMA/H₂O) is useful compositions for depositingAl₂O₃. Cyclopentadienyl compounds of the metal M or of Ln can beutilized to deposit MO or Ln₂O₃ in cyclic ALD processes utilizing ozone(O₃) or water vapor (H₂O). Beta-diketonates of M or Ln can be utilizedto deposit MO or Ln₂O₃ in a cyclic ALD process in which reactive pulsesof the beta-diketonate metal precursor alternate with pulses of O₃.

For deposition of an aluminum oxide protective coating, a precursor forthe metal, e.g., trimethylaluminum is selected together with an oxiccomponent, such as ozone or water, and the coating conditions areidentified, which may illustratively comprise an ALD sequence ofTMA/purge/H₂O/purge or a sequence of TMA/purge/O₃/purge, with asubstrate temperature that may for example be in a range of from 150° C.to 350° C., and a coating thickness in a range of from 5 nm to 5 μm. Thepulse and purge times for the process sequence can then be determinedfor a particular reactor and the geometry of the surface or componentthat is being coated.

As a general approach, suitable metal oxides for protecting surfacesfrom dialuminum hexachloride, and suitable metal oxides for protectionof surfaces from metal halide vapor can be selected based on thefollowing methodology.

For deposition of an aluminum oxide protective coating, a precursor forthe metal, e.g., trimethylaluminum is selected together with an oxiccomponent, such as ozone or water, and the coating conditions areidentified, which may illustratively comprise an ALD sequence ofTMA/purge/H₂0/purge or a sequence of TMA/purge/0₃/purge, with asubstrate temperature that may for example be in a range of from 150° C.to 350° C., and a coating thickness in a range of from 5 nm to 5 μm. Thepulse and purge times for the process sequence can then be determinedfor a particular reactor and the geometry of the surface or componentthat is being coated.

As a general approach, suitable metal oxides for protecting surfacesfrom dialuminum hexachloride, and suitable metal oxides for protectionof surfaces from metal halide vapor can be selected based on thefollowing methodology.

The temperature at which dialuminum hexachloride exposure will occur inthe semiconductor equipment is first specified, and then the chemicalreactions are identified for the metals of the surfaces and componentsof the semiconductor manufacturing equipment with the chemical reagentsthat will be contacting such surfaces and components. For these chemicalreactions at the specified temperature, the enthalpy and entropychanges, as well as the free energy and reaction constant, can beidentified, as shown for example in Table 1 below.

TABLE 1 ΔH ΔS ΔG T (kJ) (J/K) (kJ) K 2 Cr_((s)) + Al₂Cl_(6(g)) ->2CrCl_(3(s)) + Al_((s)) 120° C. 185 −207 267 10 − 36 Cr₂O_(3(s)) +Al₂Cl_(6(g)) -> 2CrCl_(3(s)) + Al₂O_(3(s)) 120° C. −354 −256 −253 10 +33 Al₂O_(3(s)) + Al₂Cl_(6(g)) -> 2AlCl_(3(s)) + Al₂O_(3(s)) 3CaO_((s)) +Al₂Cl_(6(g)) -> 3CaCl_(2(s)) + Al₂O_(3(s)) 100° C. −860 −206 −784 5.0E+109 3MgO_((s)) + Al₂Cl_(6(g)) -> 3MgCl_(2(s)) + Al₂O_(3(s)) 100°C. −497 −226 −413 6.5E+57 3BeO_((s)) + Al₂Cl_(6(g)) -> 3BeCl₂(s) +Al₂O_(3(s)) 100° C. −38.0 −226 46.4 3.2E−7  La₂O_(3(s)) + Al₂Cl_(6(g))-> 2LaCl_(3(s)) + Al₂O_(3(s)) 100° C. −727 −269 −627 5.4E+87Sc₂O_(3(s)) + Al₂Cl_(6(g)) -> 2ScCl_(3(s)) + Al₂O_(3(s)) 100° C. −320−239 −231 2.4E+32 Y₂O_(3(s)) + Al₂Cl_(6(g)) -> 2YCl_(3(s)) + Al₂O_(3(s))100° C. −474 −243 −384 4.9E+53 2TiN _((s)) + Al2Cl6(g) -> 2TiCl_(3(s)) +2AlN_((s)) 100° C. −106 −207 −29 1.2E+4  2Au(s) + Al2Cl6(g) =2AuCl3(s) + 2Al(s) 100° C. 1062 −170 1125  2.5E−158 6Ag(s) + Al2Cl6(g) =6AgCl(s) + 2Al(s) 100° C. 537 −80 567 3.7E−80 Al2O3(s) + 6HBr(g) =2AlBr3(g) + 3H2O(g) 100° C. 346 21 229 3.7E−87 Al2O3(s) + 6HCl(g) =Al2Cl6(g) + 3H2O(g) 100° C. 208 −135 259 5.8E−37 2Ni(s) + SiCl4(l) =2NiCl2(s) + Si(s) 100° C. 74 −92 108 6.6E−16 Ni(s) + GeF4(g) = NiF2(s) +GeF2(s) 100° C. −124 −169 −61 3.2E+8  Al2O3(s) + 1.5GeF4(g) = 2AlF3(s) +1.5GeO2(s) 100° C. −428 −305 −314 8.6E+43 Cr2O3(s) + 1.5GeF4(g) =2CrF3(s) + 1.5GeO2(s) 100° C. −265 −287 −158 1.3E22   Au(s) + 1.5GeF4(g)= AuF3(s) + 1.5GeF2(s) 100° C. 452 −250 546 3.2E−77 Cu(s) + GeF4(g) =CuF2(s) + GeF2(s) 100° C. −9 −1667 55 3.3E−8  Au(s) +2HF(g) = AuF2(s) +H2(g) 100° C. 310 −155 368 3.5E−52 A Mo_(x/2(s)) + Al₂Cl6_((g)) -> AMCl_(x(s)) + Al₂O_(3(s)) 120° C. ≥0 A Mo_(x/2(s)) + NX_(y(g)) -> AMX_(x(s)) +NO_(2y(s)) 120° C. ≥0wherein A is the number of moles, X is a halide, and N is an arbitrarymetal. For example, NX_(y) could be HfCl₄ or WCl₆.

The reaction in the first line of Table 1 will not cause corrosion ofthe metal in the semiconductor manufacturing equipment, because the freeenergy of the reaction is positive. The reaction in the second line ofTable 1, however, can cause corrosion. By changing the surface oxide ofthe stainless steel semiconductor manufacturing equipment from Cr₂O₃ toAl₂O₃, the driving force for the reaction goes to zero. Alternatively,as shown in the third line of Table 1, the protective oxide can bechosen from any metal oxide MO_(x) for which the free energy of thereaction is greater than or equal to zero (and in which x has anystoichiometrically appropriate value). Further, as shown in the fourthline of Table 1, if a general metal halide vapor NX_(y) is corrosivebehavior, and Al₂O₃ coatings may be usefully employed to provide aprotective film against such corrosive agents. Titanium tetrachloride isquite corrosive and would have a positive ΔG for Y₂O₃.

In specific embodiments, Al₂O₃ is utilized as a protective coatingmaterial having a positive ΔG for hydrogen bromide exposure of stainlesssteel surfaces. In other embodiments, Al₂O₃ is utilized as a protectivecoating material having a positive ΔG for hydrogen chloride exposure ofstainless steel surfaces. In still other embodiments, nickel is utilizedas a protective coating material having a positive ΔG for silicontetrachloride exposure of stainless steel surfaces.

In additional embodiments, protective coatings having a positive ΔG onstainless steel surfaces in exposure to germanium tetrafluoride maycomprise any of nickel, Al₂O₃, Cr₂O₃, gold, nitrides such as titaniumnitride (TiN), glasses, and copper. Passivation with germaniumtetrafluoride is effective for stainless steel and nickel due to theformation of surface Ni—F, Cr—F, and Fe—F species, which can beconsidered as NiF₂, CrF₃, or FeF₃ layers overlying nickel or stainlesssteel.

In other embodiments, gold is utilized as a protective coating materialhaving a positive ΔG for hydrogen fluoride exposure of stainless steelsurfaces.

In various embodiments, protective coatings for stainless steel andcarbon steel include metals such as nickel and metal alloys. In otherembodiments, protective coatings for such services may include polymericmaterials, such as polytetrafluoroethylene (PTFE) or PTFE-likematerials, including protective coatings of materials commerciallyavailable under the trademarks Teflon® and Kalrez®. Protective coatingsmay also be employed to avoid embrittlement of stainless steel caused byexposure to hydride gases, and such protective coatings may be formed ofor otherwise comprise materials such as aluminum, copper, or gold

The reactive agents for which protective coatings are provided on thesurfaces may be of solid, liquid and/or gas form, and may be in amixture or a solution including one or more solvents.

Concerning ΔG more generally, stability in a range of 10⁻⁴<K<10⁻⁴ can beswitched by pressure or temperature changes, and when K>10⁻⁴ there willbe little corrosion under any conditions.

The dense, pin-hole free coatings of the present disclosure, as formedby ALD or other vapor phase deposition techniques, are distinguishablefrom native oxide surfaces. Native oxide films typically form at or nearroom temperature, are crystalline, and the oxidation associated withsuch native oxide films may be incomplete. Such native oxide films aremore reactive than the vapor phase deposition coatings, e.g., ALDcoatings, of the present disclosure. The dense, thick, pin-hole freevapor phase deposition coatings of the present disclosure are amorphousand conformal.

In the case of alumina coatings on stainless steel, as formed inaccordance with the present disclosure, cleaning or other pre-treatmentsteps may be employed before the deposition of the Al₂O₃ coating. Forexample, electropolishing or decreasing treatments may be employed, or acombination of such treatments, as may be desirable or advantageous in aspecific implementation of the disclosure. Any other suitable cleaningor pre-treatment steps may additionally, or alternatively, be utilized.

In respect of aluminum trichloride, it is noted that AlCl₃ does notdissolve in solvents, or in oil or grease, however, oil or grease may bepresent as a heat transfer agent, e.g., in a solid delivery vaporizer inwhich AlCl₃ or other chemical is provided for volatilization when thevaporizer is heated, to provide a vapor stream that is dispensed fromthe vessel. For example, the AlCl₃ or other chemical to be delivered maybe mixed with a high boiling point, inert oil or grease to form a pastethat then is loaded onto trays or other support surface in the soliddelivery vessel. The oil or grease then serves as a heat transfer agent,and as a medium to capture small particles and prevent them from beingentrained in the vapor flow. These captured small particles then areretained in the oil or grease until they are vaporized and thereby passout of the heat transfer agent and ultimately from the vaporizer vessel.In such manner, the oil or grease may improve heat conductivity andenable lower delivery temperature of the vaporizer to be achieved.

Referring now to the drawings, FIG. 1 is a schematic representation of adeposition furnace 102 of a semiconductor wafer processing tool 100according to one aspect of the present disclosure.

The furnace 102 defines a heated interior volume 104 in which isdisposed a liner 110 separating the interior volume into an inner volume108 within the liner 110, and an exterior volume 106 outside the liner,as shown. A wafer carrier 112 having wafers 114 mounted therein ispositioned in the inner volume 108 within the liner 110 so that thewafers may be contacted with process gas in the furnace.

As shown in the FIG. 1 drawing, a first process gas may be supplied tothe inner volume 108 of the furnace from first process gas source 116via first process gas feed line 118. In like manner, a second processgas may be supplied to the inner volume 108 of the furnace from secondprocess gas source 120 via second process gas feed line 122. The firstand second process gases may be concurrently or consecutively introducedto the furnace in the operation of the tool. The first process gas mayfor example comprise an organometallic precursor for vapor deposition ofthe metal component on a wafer substrate in the wafer carrier 112. Thesecond process gas may for example comprise a halide cleaning gas. Thegas introduced to the inner volume 108 of the furnace flows upwardlywithin the liner and upon flowing out of the upper open end of the liner110, flows downwardly in the annular exterior volume 106. Such gas thenflows out of the furnace in discharge line 124 to the abatement unit 126in which the effluent gas from the furnace is treated to removehazardous components therefrom, with discharge of treated gas in ventline 128 to further treatment or other disposition. The abatement unit126 may comprise wet and/or dry scrubbers, catalytic oxidationapparatus, or other suitable abatement equipment.

In accordance with the present disclosure, the surfaces of the furnaceand liner component are coated with a layer of Al₂O₃ so that they resistchemical attack from dialuminum hexachloride that could in turn renderthe wafers 114 in the furnace deficient or even useless for theirintended purpose.

FIG. 2 is a schematic representation of a deposition furnace processsystem according to another aspect of the disclosure, for coating wafersusing Al₂Cl₆ vapor, utilizing a solid source delivery vaporizer in theform of an ampoule for vaporizing AlCl₃ to form the Al₂Cl₆ vapor,wherein the trays and internal surfaces of the ampoule are coated withAl₂O₃, as well as all of the valves, tubing and filters downstream ofthe ampoule being coated with Al₂O₃.

As illustrated, the ampoule is provided with a supply of argon carriergas from a supply vessel (“Ar”), and the carrier gas is flowed throughthe carrier gas feed line containing a mass flow controller (“MFC”) tothe ampoule. In the ampoule, the carrier gas is contacted with theAl₂Cl₆ vapor produced by heating the ampoule to volatilize the solidAlCl₃ supported on trays therein, and the volatilized Al₂Cl₆ then isflowed to the furnace, containing wafers on which aluminum is depositedfrom the Al₂Cl₆ vapor. Co-reactant for the deposition may be introducedto the furnace as shown, by the co-reactant feed line to the furnace.The fluid flow through the furnace is controlled by the pump andpressure control valve assembly, to maintain conditions in the furnaceappropriate for the deposition operation therein.

As mentioned, the trays and internal surfaces of the ampoule are coatedwith Al₂O₃, as are all of the flow circuitry surfaces and componentstherein downstream from the ampoule to prevent attack by the dialuminumhexachloride vapor. The filters in the flow circuitry may be of a typecommercially available under the trademarks Wafergard™ and Gasketgard™from Entegris, Inc., Billerica, Mass., USA with metal filter elements.

FIG. 3 is a perspective, partial breakaway view of a vaporizer ampouleof a type suitable for use in the deposition furnace process system ofFIG. 2. The vaporizer ampoule includes a container 300 having holders tohelp promote contact of a gas with vapor from material supported by theholders. The container has a plurality of holders 310, 320, 330, 340,350, and 360 defining respective support surfaces 311, 321, 331, 341,351, and 361. The container has a bottom wall having a surface 301 and asidewall 302 to help define a generally cylindrical interior region incontainer 300 with a generally circular opening at or near the top ofcontainer 300. The inner diameter of the generally cylindrical interiorregion in a specific embodiment may be in the range of, for example,approximately 3 inches to approximately 6 inches.

Although container 300 is illustrated in FIG. 3 as having an integralbody, the container may be formed from separate pieces. The containerthis provides an ampoule for vaporizing material for delivery toprocessing equipment.

As illustrated in FIG. 3, holder 310 may be positioned over bottomsurface 301 to define support surface 311 over bottom surface 301,holder 320 may be positioned over holder 310 to define support surface321 over support surface 311; holder 330 may be positioned over holder320 to define support surface 331 over support surface 321; holder 340may be positioned over holder 330 to define support surface 341 oversupport surface 331; holder 350 may be positioned over holder 340 todefine support surface 351 over support surface 341; and holder 360 maybe positioned over holder 350 to define support surface 361 over supportsurface 351. Although illustrated in FIG. 3 as using six holders 310,320, 330, 340, 350, and 360, any suitable number of holders may beemployed in various embodiments of the vaporizer.

As illustrated in FIG. 3, a generally annular support 304 may be placedon bottom surface 301 in the interior region of container 300 to supportholder 310 above bottom surface 301. A tube 305 may then extend throughopenings in holders 360, 350, 340, 330, 320, and 310 in a generallycentral portion of the interior region of container 300 to a locationbetween holder 310 and bottom surface 301.

As one example, the vaporizer of FIG. 3 may be modified by coupling abaffle or diffuser at the end of tube 305 to help direct gas flow overmaterial supported on bottom surface 301. In embodiments in which gas isintroduced at or near a lowermost holder supporting material to bevaporized, introduced gas may be directed to flow over and/or throughmaterial supported by the lowermost holder using any suitable structure.

As illustrated in FIG. 3, container 300 may have a collar around theopening at the top of container 300, and a lid 306 may be positionedover the collar and secured to the collar using screws, such as screw307 for example. A groove may optionally be defined around the openingat the top of the collar to help position an O-ring 308 betweencontainer 300 and lid 306. O-ring 308 may be formed from any suitablematerial such as, for example, Teflon®, any suitable elastomer, or anysuitable metal, such as stainless steel for example. Lid 306 may definethrough a generally central region of lid 306 an opening through which apassage or inlet defined at least in part by tube 305 may extend intothe interior region of container 300. As lid 306 is secured to thecollar for container 300, lid 306 may press against O-ring 308 to helpseal lid 306 over the collar and may press against a collar around tube305 to help press lid 306 against holders 360, 350, 340, 330, 320, and310. An O-ring for holders 360, 350, 340, 330, 320, and 310 may then becompressed to help seal holders 360, 350, 340, 330, 320, and 310 againstone another and/or against tube 305. A valve 381 having an inletcoupling 391 may be coupled to tube 305 to help regulate theintroduction of gas into container 300. Lid 306 may also define anopening through which a passage or outlet defined at least in part by atube may extend into container 300. A valve 382 having an outletcoupling 392 may be coupled to the tube to help regulate the delivery ofgas from the container.

As illustrated in FIG. 3, a generally circular frit 370 may bepositioned over top holder 360 to help filter solid material from gasflow directed over material supported by holder 360 prior to deliverythrough the outlet defined through lid 306. Frit 370 may define througha generally central region of frit 370 a generally circular openingthrough which tube 305 may extend. Frit 370 may be pressed over holder360 in any suitable manner using any suitable structure as lid 306 issecured to container 300 to help seal frit 370 over holder 360. Thevaporizer may comprise in addition to or in lieu of frit 370 a fritpositioned in the passage or outlet for gas delivery from container 300and/or one or more fits positioned in one or more passageways throughone or more of holders 310, 320, 330, 340, 350, and 360. The frit(s) inthe vaporizer may additionally be coated with Al₂O₃. In like manner, anyother internal components in the vaporizer may be coated with Al₂O₃, sothat all surfaces and components in the interior volume of the vaporizerare coated with Al₂O₃.

In the FIG. 3 vaporizer, a bypass passage defined by tubing 395 coupledbetween valves 381 and 382 may be used to help purge valves 381 and 382,inlet coupling 391, and/or outlet coupling 392. A valve 383 mayoptionally be coupled to tubing 395 to help regulate fluid flow throughthe bypass passage. An inlet/outlet coupling 397 may optionally be usedto help define an additional inlet/outlet for the interior region ofcontainer 300 to help purge the interior region.

FIG. 4 is a micrograph, at 15K magnification, of the surface of a porousmetal fit of a type usefully employed in filter elements, according toanother aspect of the disclosure.

The high surface area of the frit can be advantageously coated by ALD,wherein metal precursor and oxidizing co-reactant reach the surface inseparate, self-limiting pulses. To coat the frit with Al₂O₃ alternatingpulses of trimethylaluminum and water or O₃/O₂ mixtures may be employed.Specific conditions can be empirically determined by increasing thepulse lengths of each step until all surfaces are coated. Depositiontemperatures from 100-400° C. may be employed to deposit useful films inspecific embodiments.

It will be appreciated that other aluminum sources may be employed inthe broad practice of the present disclosure, as for example AlCl₃,other AlR₃ (alkyl) compounds wherein R₃ is an organo moiety, or othervolatile Al compounds. Other oxygen sources such as N₂O, O₂, alcohols,peroxides, etc. can also be used with the aluminum source reagents todeposit Al₂O₃ or related AlO_(x) materials, in such practice of thepresent disclosure.

The features and advantages of the present disclosure are more fullyshown by the following examples, which are of illustrative character tofacilitate understanding of the disclosure.

EXAMPLE 1

Electropolished 316L stainless steel samples were rinsed withisopropanol to clean the surface. Two samples were coated with Al₂O₃ byatomic layer deposition (ALD). One sample was subjected to 100 ALDcycles of trimethylaluminum/purge/water/purge and the other sample wassubjected to 1000 cycles of the same ALD process. The depositiontemperature was 150° C. Two samples were not coated. Both coated samplesand one of the uncoated samples were loaded into a glass ampoule withsolid AlCl₃ powder in a nitrogen-purged glovebox to prevent moisture oroxygen from interacting with the samples or with the AlCl₃. The glassampoule was then sealed with a PTFE cap. The ampoule with AlCl₃ andstainless steel samples was heated to 120° C. for 10 days. At the end of10 days, the ampoule was cooled and brought back into the glovebox. Thesamples were removed from the AlCl₃ under this inert environment. Themass gain of the samples was 0.4 to 0.7 mg (<0.15%). All of the surfaceslooked pristine to the eye. Next, these three samples and an additionalsample that had not seen any exposure to AlCl₃ were examined in thescanning electron microscope (SEM) on their top surfaces and thencross-sectioned by focused ion beam (FIB) to determine whether there wasany attack of the surface.

FIG. 5 shows the surface images of a sample that did not see any AlCl₃.The surface of this sample is clean and shows the major elements of thestainless steel: Fe, Cr, and Ni.

FIG. 6 shows the uncoated sample that was exposed to AlCl₃ It can beseen that there is significant surface residue on this sample with theaddition of Al and Cl to the major components of the stainless steel.

FIG. 7 shows a cross-section of the sample that was not exposed toAlCl₃. It is clear that there is no surface attack.

FIG. 8 shows the uncoated sample that was exposed to AlCl₃. There is aline to compare to the surface so that it is clear that there wassurface attack of 0.1 to 0.2 microns underneath the area that had Al-and Cl-containing residue.

FIG. 9 shows a different area of the sample that was exposed to AlCl₃with no surface coating. Native oxide is present on the untreatedstainless steel surface. In this area, multiple pits are clearlyvisible.

In contrast, FIG. 10 shows the cross-section of the surface that had acoating of 100 cycles of TMA/H₂O prior to exposure to AlCl₃ at 120° C.In this case there is still Al- and Cl-containing residue adhered to thesurface, but there is no evidence of any attack of the surface of thestainless steel.

Likewise, FIG. 11 shows the cross-section of the surface that had acoating of 1000 cycles of TMA/H₂O prior to exposure to AlCl₃ at 120° C.In this case there is still Al- and Cl-containing residue adhered to thesurface, but there is no evidence of any attack of the surface of thestainless steel.

EXAMPLE 2

In a specific empirical assessment, the efficacy of alumina coatings wasevaluated, in exposure to aluminum trichloride (AlCl₃) in a first test,and in exposure to tungsten pentachloride (WCl₅) in a second test.

In the first test, sample coupons of electropolished 316L stainlesssteel were either coated with 470 Å of Al₂O₃ or uncoated. One sample ofeach type was placed in one of two containers with solid AlCl₃. Both ofthe containers were loaded, sealed, and pressurized to 3 psig withhelium inside of a N₂ purged glovebox, with O₂ and H₂O levels below 0.1ppm. Outboard He leak tests determined that one of the containers had aleak rate below 1E-6 standard cubic centimeter per second (sec/s), whichwas the resolution limit of the measurement, and the other container hada leak rate of 2.5E-6 sec/s. The containers were heated in the same ovento 155° C. for nine days, cooled, and the coupons were removed in theglovebox. Table 2 shows the mass changes of the various coupons.

TABLE 2 Mass Changes of various coupons soaked in AlCl₃ for 9 days at155° C. leak rate initial mass post mass change sample type ID sec He/sg g g % change coated coupon 2 2.50E−06 3.3986 3.3967 −0.0019 −0.06%coated coupon 3  <1E−6 3.3896 3.3896 0.0000 0.00% uncoated coupon 122.50E−06 3.3913 3.3824 −0.0089 −0.26% uncoated coupon 13  <1E−6 3.45543.4554 0.0000 0.00%

FIG. 12 is a composite photograph of the sample coupons of Table 2 afterthe nine-day exposure to AlCl₃ at 155° C., in which the respectivecoupons are identified by the same ID numbers as are set out in Table 2.

From Table 2 it is evident that the mass changes were only quantifiablewhen there was a measurable leak of the container. In this corrosiveexposure, the loss of mass of the samples as tabulated in Table 2 andthe composite photograph of the respective sample coupons in FIG. 12show that the coated sample coupon 2 was in substantially bettercondition than the uncoated sample coupon 12 after the nine-day exposureto ACl₃ at 155° C. There was no change in the Al₂O₃ coating thickness asmeasured by XRF.

In the second test, sample coupons of electropolished 316L stainlesssteel were either coated with 470 Å thick coatings of Al₂O₃ or wereuncoated. Sample coupons were placed in containers with solid WCl₅, with165° C., 180° C. and 220° C. temperature conditions being maintained inrespective containers. All of the containers were loaded and scaledinside of a N₂ purged glovebox, with O₂ and H₂O levels below 0.1 ppm.The containers then were heated in an oven for ten days, cooled, and thesample coupons were removed from the respective containers, in theglovebox.

Thickness measurements were made by x-ray fluorescence (XRF)spectroscopy technique, to assess change in coating thickness of thealumina coating, from initial measured thickness. Table 3 contains theXRF measurements of Al₂O₃ thickness before and after exposure to WCl₅,for two sample coupons maintained at 165° C. for 10 days in suchexposure, for two sample coupons maintained at 180° C. for 10 days insuch exposure, and for one sample coupon maintained at 220° C. for 10days in such exposure. Approximately 15-30 Å of the coating wastypically etched away in the cleaning process.

TABLE 3 XRF measurements of Al₂O₃film thickness before and afterexposure to WCl₅ at various temperatures for 10 days. Initial AlOx FinalAlOx Change in T ° C. thickness, Å thickness, Å thickness, Å 165 462.4439.6 −22.8 165 467.5 450.8 −16.7 180 474.8 447.8 −27.0 180 477.5 411.7−65.8 220 476.1 182.8 −293.4

FIG. 13 is a top-down scanning electron microscope (SEM) micrograph ofthe sample exposed to WCl₅ at 220° C. for 10 days, and FIG. 14 is afocused ion beam (FIB) cross-section of the edge of the coating in suchsample.

Coated and uncoated samples in this second test showed no sign ofcorrosion visually or by SEM examination or by weight change. However,at the higher temperature, a significant amount of the Al₂O₃ coating wasremoved. Both samples at 165° C. were etched in an amount consistentwith the cleaning process. One of the samples at 180° C. lost 27 Å ofthickness, consistent with cleaning, but the other sample lostapproximately 66 Å of thickness, which is significantly above that ofcleaning. At 220° C., about 60% of the coating was removed, as shown inFIG. 13 in which the alumina coating is removed in some areas (lighterarea portion) and is intact in others (darker area portion). In FIG. 14,the micrograph shows the coating intact to the right, and the edge ofthe coated area is indicated by the arrow.

It will be recognized that although the disclosure is directedillustratively to semiconductor manufacturing equipment, the protectivecoating approach of the present disclosure is likewise applicable toother gas processing apparatus for the manufacture of other products,such as flat-panel displays, photovoltaic cells, solar panels, etc.where surfaces in the process equipment are susceptible to attack byvapor phase components that react with oxides on such services to formreaction products that are deleterious to the products made andprocesses conducted with such equipment.

Set out below is a further aspect of the disclosure relating to thinfilm atomic layer deposition coatings.

While various compositions and methods are described, it is to beunderstood that this invention is not limited to the particularmolecules, compositions, designs, methodologies or protocols described,as these may vary. It is also to be understood that the terminology usedin the description is for the purpose of describing the particularversions or embodiments only, and is not intended to limit the scope ofthe present invention.

It must also be noted that as used herein, the singular forms “a”, “an”,and “the” include plural reference unless the context clearly dictatesotherwise. Thus, for example, reference to a “layer” is a reference toone of more layers and equivalents thereof known to those skilled in theart, and so forth. Unless defined otherwise, all technical andscientific terms used herein have the same meanings as commonlyunderstood by one of ordinary skill in the art.

Methods and materials similar or equivalent to those described hereincan be used in the practice or testing of embodiments of the presentdisclosure. All publications mentioned herein are incorporated byreference in their entirety. Nothing herein is to be construed as anadmission that the invention claimed herein is not entitled to antedatesuch publications by virtue of prior invention. “Option” or “optionally”means that the subsequently described event or circumstance may or maynot occur, and that the description includes instances wherein the eventoccurs and instances where it does not. All numeric values herein can bemodified by the term “about,” whether or not explicitly indicated. Theterm “about” generally refers to a range of numbers that one of skill inthe art would consider equivalent to the recited value (i.e., havingsimilar function or result). In some embodiments the term “about” refersto ±10% of the stated value, in other embodiments the term “about”refers to ±2% of the stated value. While compositions and methods aredescribed in terms of “compromising” various components and steps, suchterminology should be interpreted as defining essentially closed orclosed member groups.

As used herein, the term “film” refers to a layer of deposited materialhaving a thickness below 1000 micrometers, e.g., from such value down toatomic monolayer thickness values. In various embodiments, filmthicknesses of deposited material layers in the practice of theinvention may for example be below 100, 50, 20, 10, or 1 micrometers, orin various thin film regimes below 200, 100, 50, 20, or 10 nanometers,depending on the specific application involved. As used herein, the term“thin film” means a layer of a material having a thickness below 1micrometer.

Although the disclosure has been set forth herein with respect to one ormore implementations, equivalent alterations and modifications willoccur to others skilled in the art based upon a reading andunderstanding of this specification. The disclosure includes all suchmodifications and alterations. In addition, while a particular featureor aspect of the disclosure may have been disclosed with respect to onlyone of several implementations, such feature or aspect may be combinedwith one or more other features or aspects of the other implementationsas may be desired and advantageous for any given or particularapplication. Furthermore, to the extent that the terms “includes”,“having”, “has”, “with”, or variants thereof are herein, such terms areintended to be inclusive in a manner similar to the term “comprising.”Also, the term “exemplary” is merely meant to mean an example, ratherthan the best. It is also to be appreciated that features, layers and/orelements depicted herein are illustrated and/or taught with particulardimensions and/or orientations relative to one another for purposes ofsimplicity and ease of understanding, and that the actual dimensionsand/or orientations may differ substantially from that illustratedand/or taught herein.

Thus, the disclosure, as variously set out herein in respect offeatures, aspects and embodiments thereof, may in particularimplementations be constituted as comprising, consisting, or consistingessentially of, some or all of such features, aspects and embodiments,as well as elements and components thereof being aggregated toconstitute various further implementations of the disclosure. Thedisclosure correspondingly contemplates such features, aspects andembodiments, or a selected one or ones thereof, in various permutationsand combinations, as being within the scope of the present disclosure.Further, the disclosure contemplates embodiments that may be defined byexclusion of any one or more of the specific features, aspects, orelements that are disclosed herein in connection with other embodimentsof the disclosure.

In accordance with one aspect of the present disclosure, there isprovided a thin film coating comprised of one of more layers, where atleast one layer is deposited by atomic layer deposition.

In accordance with aspects of the disclosure, the following areprovided:

ALD coating with a film thickness of more than 1 Å and in someapplications more than 10,000 Å

ALD coating providing a very dense, pine-hole-free, defect-free layer.

Thin film coating intended for deposition applications on a multitude ofparts, but not directly for the actual IC device (transistor)manufacturing on a Si wafer.

ALD coating may be comprised of insulating metal oxides such as alumina(Al₂O₃), yttria (Y₂O₃), zirconia (ZrO₂), titania (TiO₂), etc., andmetals such as platinum, niobium, or nickel.

ALD coating may be deposited between RT (room temperature) and 400° C.

ALD coating may be a single film with a defined stoichiometry, such asfor example a 1 micron thick alumina layer, or several layers such asfor example {0.25 micron titania+0.5 micron alumina+0.25 micronzirconia} or a true multilayer structure, such as for example {1 atomiclayer titania+2 atomic layers alumina}×n, with n being in a range of 1to 10,000, or combinations thereof.

The thin film coating where the ALD layer is combined with another layerthat is deposited by a different deposition technique, such as PE-CVD,PVD, spin-on or sol-gel deposition, atmospheric plasma deposition, orthe like.

Total film thickness between 1 micron and 100 microns.

Portion of ALD coating thickness of the entire stack to be less or equalthan 2 microns, with the 2 microns being in one or more distinct layers.

Other coating materials being selected from the group of oxides, such asalumina, aluminum-oxy nitride, yttria, yttria-alumina mixes, siliconoxide, silicon oxy-nitride, transition metal oxides, transition metaloxy-nitrides, rare earth metal oxides, rare earth metal oxy-nitrides.

Ability to pattern ALD coating:

Method 1: Uniformly coat part and then etch back unwanted materialsthrough a mask (the etch back can be mechanical, e.g., bead blast,physical, e.g., plasma ions, or chemical, e.g., plasma or wet etch).

Method 2: Mask unwanted area, ALD coat and then remove masked areas. Themask can be a sealed sheet, or fixture or photo resist (lift-offtechnique).

Method 3: Create pattern on substrate with a surface termination thatblocks the ALD film growth. For example, a surface termination layer maybe employed that has “zero” sticking coefficient for H₂O and TMA(trimethylaluminum). As used herein, a surface termination layer is aself-limiting layer, e.g., a self-limiting ALD layer. As used herein,the sticking coefficient is the ratio of the number of adsorbate atoms(or molecules) that adsorb, or “stick,” to a surface, to the totalnumber of items that impinge on that surface during the same period oftime.

In accordance with aspects of the disclosure, the following applicationsare provided:

Applications:

Defect-free, pin-hole-free, dense, electrical insulation of parts.

Ability to coat parts with high-aspect ratio features. Examples: (1)Parts with deep holes, channels and 3-dimensional features, (2) hardwaresuch as screws and nuts, (3) porous membranes, filters, 3-dimensionalnetwork structures, (4) structures with connected pore matrices.

Electrical insulation layer: High dielectric breakdown strength and highelectrical resistance (low leakage). This is achieved with ALD Al₂O₃.Using multi-layers of titania-alumina-zirconia (TAZ) further improveelectrical insulator performance. There are variousmultilayer-configurations:

X nm TiO₂+Y nm Al₂O₃+Z nm ZrO₂

[U nm TiO₂+V nm Al₂O₃+W nm ZrO₂T] times n

X nm TiO₂+[V nm Al₂O₃+W nm ZrO₂T] times m

etc.; wherein X, Y, Z, U, V, and W may each be in a range of from 0.02nm to 500 nm, and wherein each of n and m may be in a range of from 2 to2000.

Chemical and etch-resistant coating: The ALD layer can be alumina,yttria, ceria, or similar. The total etch resistant coating may becomprised of (1) ALD layer only, (2) combination of PVD, CVD, and ALD,(3) ALD may be overcoat and serve as sealant layer, as discussed morefully hereinafter, (4) ALD may be underlayer to provide robustfoundation, and (5) ALD may be interspersed between CVD and/or PVDcoating layers.

The ALD coating may provide chemical resistance for applications such asadvanced batteries, gas filters, liquid filters, electro-plating toolcomponents, plasma-wetted components (to protect against fluorine andother halogen attack), etc.

The ALD coating may serve as corrosion-resistant coating

Diffusion barrier layer, the ALD layer, which is dense, conformal andpin-hole free provides excellent trace metal diffusion barriercharacteristics

The ALD layer may serve as an adhesion layer between an underlyingsubstrate (glass, quartz, aluminum, anodized aluminum, alumina,stainless steel, silicon, SiOx, AlON, etc.) and an overlying coatinglayer (PVD yttria, PVD AlON, PVD Al₂O₃, CVD SiOx, CVD SiO_(x)N_(y), CVDAl₂O₃, CVD AlO_(x)N_(y), DLC, Si, SiC, etc.)

In accordance with another aspect of the disclosure, an ALD-depositedsurface sealant layer is used for coatings. ALD (atomic layerdeposition) is an established technology, which uses chemical adsorptionof two or more alternating precursors to form very dense, nearlyperfectly arranged (physically and stoichiometrically) thin films. Thetechnique allows for precisely controlled film growth, is nearly 100%conformal and will grow films at any surface location that the precursorgas can reach, including within very high aspect ratio features. In thisrespect, an ALD-deposited sealant coating can be used for the followingapplications:

(1) to overcoat and seal an existing surface and therefore provideenhanced and superior properties of that surface/part

(2) to apply an ALD sealing coating on top of a CVD, PVD, spray- orother coating to provide a sealant for the imperfections of thatcoating, such as:

(i) filling any cracks near the coating surface and therefore providinga surface that is impermeable to corrosive and etching environments

(ii) filling and sealing any micropores, coating defects, intrusions,etc. to provide a coating surface layer that is impermeable to gases andliquids and terminated with a controlled smooth, conformal sealant layer

(iii) reducing surface roughness and overall surface area of thecoating, thus providing a smooth and dense surface layer that allows forminimal attack in corrosive environments

(iv) minimizing particle generation, improving hardness, toughness andscratch resistance by providing a dense and smooth sealed surface withovercoat

In various aspects of the disclosure, the ALD sealant may be applied toparts and surfaces that require:

(a) improved etch and corrosion resistance, and/or

(b) reduced friction, wear, and improved mechanical abrasion resistance

The ALD sealant layer at the same time may also serve as a diffusionbarrier, and it has the ability to control surface electrical propertiesas well as the surface termination, such as hydrophilicity andhydrophobicity.

A further aspect of the disclosure involves use of ALD technology withfibrous metal membranes with chemically resistant coatings like alumina,yttria, or other coatings of this type. The ALD technology allows gasesto penetrate the porous filter and coats over the fibrous membraneproviding resistance to corrosive gases.

This aspect of the disclosure provides a deposition gas-based techniquethat can penetrate small micron size openings and coat uniformly overthe fibers.

This aspect of the disclosure has been demonstrated by depositingalumina coating on a 4-micron Ni-based gas filter made by Entegris, Inc.of Billerica, Mass., U.S.A.

The ALD technology of this disclosure offers many benefits, such as:

1) Coating penetration into small features like micron size porosity ofthe filters ensuring complete coverage

2) Hermetic sealing of the fibers thus protecting the filter membranes

3) Various different coatings can be deposited used this technique

The disclosure also contemplates use of ALD coatings to improve theprocessing characteristics of the substrate article or equipment that iscoated. For example, ALD films may be employed to combat blistering orother undesired phenomena that may occur during annealing of substratearticles, due to mismatches in coefficient of thermal expansion betweenlayers of a multilayer film article. Thus, ALD films may be employed inthe multilayer film structure to ameliorate such material propertydifferences, or otherwise to improve electrical, chemical, thermal, andother performance properties of the ultimate product article.

The disclosure further contemplates the use of ALD coatings to protectfluid-contacting surfaces of apparatus handling fluids that may presenta risk of chemical attack in the use of such apparatus. Such apparatusmay include for example fluid storage and dispensing packages employedto supply gas to semiconductor manufacturing tools, where the fluid mayadversely affect the flow path components and downstream processequipment. Fluids that may present a specific issue in particularapplications may include halide gases such as fluorides of boron orgermanium. Thus, the coatings of the present disclosure may be employedto enhance the performance of process equipment, flow circuitry, andsystem components, in these and other applications.

In a further aspect, the disclosure relates to a composite ALD coating,comprising layers of different ALD product materials. The different ALDproduct materials may be of any suitable type, and may for examplecomprise different metal oxides, e.g., at least two metal oxidesselected from the group consisting of titania, alumina, zirconia, oxidesof the formula MO wherein M is Ca, Mg, or Be, oxides of the formulaM′O₂, wherein M′ is a stoichiometrically acceptable metal, and oxides ofthe formula Ln₂O₃ wherein Ln is a lanthanide element, such as La, Sc, orY. In other embodiments, the composite ALD coating may include at leastone layer of alumina. In still other embodiments, the composite ALDcoating may include at least one layer of titania, or zirconia, or othersuitable material.

Such composite ALD coating may comprise different metals as thedifferent ALD product materials, e.g., at least two metals selected fromthe group consisting of platinum, niobium, and nickel. Any suitablediffering metals can be employed.

In other embodiments, the different ALD product materials may comprise ametal oxide material as a first ALD product material in a first layer ofthe composite coating and a metal as a second ALD product material in asecond layer of the composite coating. The metal oxide material may forexample be selected from the group consisting of alumina, titania, andzirconia, and the metal is selected from the group consisting ofplatinum, niobium, and nickel.

The composite ALD coating described above may have any suitable numberof layers, e.g., from 2 to 10,000 layers in the coating.

The disclosure in another aspect relates to a composite coating,comprising at least one ALD layer and at least one deposited layer thatis not an ALD layer. The composite coating may for example beconstituted, so that the at least one deposited layer that is not an ALDlayer is selected from the group consisting of CVD layers, PE-CVDlayers, PVD layers, spin-on layers, sprayed layers, sol gel layers, andatmospheric plasma deposition layers. In various embodiments, the layersin the composite coating may comprise at least one layer of materialselected from the group consisting of alumina, aluminum-oxy nitride,yttria, yttria-alumina, silicon oxide, silicon oxy-nitride, transitionmetal oxides, transition metal oxy-nitrides, rare earth metal oxides,and rare earth metal oxy-nitrides.

The disclosure further contemplates a method of forming a patterned ALDcoating on a substrate, comprising forming a pattern on the substrate ofa layer of surface termination material that is effective to prevent ALDfilm growth. Such surface termination material in a particularimplementation may exhibit an essentially zero sticking coefficient forwater and trimethylaluminum. In various embodiments, the ALD coating maycomprise alumina.

The disclosure further contemplates a method of filling and/or sealingsurface infirmities of a material, said method comprising applying anALD coating on a surface infirmity of the material, at a thicknesseffecting filling and/or sealing of the infirmity. The infirmity may beof any type, and may for example be selected from the group consistingof cracks, morphological defects, pores, pinholes, discontinuities,intrusions, surface roughness, and surface asperities.

Another aspect of the disclosure relates to a filter, comprising amatrix of fibers and/or particles, the fibers and/or particles beingformed of metal and/or polymeric material, wherein the matrix of fibersand/or particles has an ALD coating thereon, wherein the ALD coatingdoes not alter pore volume of the matrix of fibers and/or particles bymore than 5%, as compared to a corresponding matrix of fibers and/orparticles lacking said ALD coating thereon, and wherein when the fibersand/or particles are formed of metal, and the ALD coating comprisesmetal, the metal of the ALD coating is different from the metal of thefibers and/or particles.

The filter may be constructed with the matrix of fibers and/or particlesin a housing that is configured for flow of fluid through the matrix forfiltration of the fluid. In various embodiments, the ALD coating maycomprise a transition metal, metal oxide, or transition metal oxide ofsuitable type. For example, the ALD coating may comprise a metal oxideselected from the group consisting of titania, alumina, zirconia, oxidesof the formula MO wherein M is Ca, Mg, or Be, and oxides of the formulaLn₂O₃ wherein Ln is a lanthanide element, La, Sc, or Y. The ALD coatingin various implementations comprises alumina. The matrix of the filtermay comprise nickel fibers and/or particles, stainless steel fibersand/or particles, or fibers and/or particles of other materials such aspolymeric materials, e.g., polytetrafluoroethylene. The filter may invarious embodiments comprise pores of any suitable diameter. Forexample, the pores may be in a range of from 1 μm to 40 μm in someembodiments, and in other embodiments may be less than 20 μm, less than10 μm, less than 5 μm or other suitable value, and in other embodimentsmay be in a range of from 1 to 10 μm, 1 to 20 μm, 20 to 40 μm, or othersuitable range of values. The ALD coating itself may be of any suitablethickness, and in various embodiments may have thickness in a range offrom 2 to 500 nm. In general, any suitable pore size and thicknesscharacteristics may be employed, as appropriate for a specific end useor application.

The filter may be of suitable character as regards its retention rating.For example, the retention rating of the filter in specific embodimentsmay be characterized by log reduction value of 9 (denoted as 9LRV) forparticles greater than 3 nm at a gas flow rate of 30 standard liters perminute gas flow or less. ALD-coated filters of the present disclosuremay be employed in various applications in which the filter is desiredto achieve a high efficiency rate of removal, as for example a rate ofremoval of 99.9999999%, determined at a most penetrating particle size,i.e., 9LRV, at a specific rated flow. The test methodology forevaluating 9LRV rating is described in Rubow, K. L., and Davis, C. B.,“Particle Penetration Characteristics of Porous Metal Filter Media ForHigh Purity Gas Filtration.” Proceedings of the 37rd Annual TechnicalMeeting of the Institute of Environmental Sciences, pp. 834-840 (1991);Rubow, K. L., D. S. Prause and M. R. Eisenmann, “A Low Pressure DropSintered Metal Filter for Ultra-High Purity Gas Systems”, Proc. of the43rd Annual Technical Meeting of the Institute of EnvironmentalSciences, (1997); and Semiconductor Equipment and MaterialsInternational (SEMI) test method SEMI F38-0699 “Test Method forEfficiency Qualification of Point-of-Use Gas Filters,” all of which areincorporated herein by reference.

Sintered metal filters/diffusers that may be coated with protectivecoatings by ALD in accordance with the present disclosure include thesintered metal filters/diffusers described in U.S. Pat. Nos. 5,114,447;5,487,771; and 8,932,381, and in U.S. Patent Application Publication2013/0305673.

Gas filters coated with protective coatings in accordance with thepresent disclosure may be variously configured. In specific illustrativeembodiments, the filters may have a pore size in a range of from 1 to 40μm, or in a range of from 1 to 20 μm, or in a range of from 20 to 40 μm,or other suitable values. Such gas filters may exist in stainless steeland nickel configurations. Both are susceptible to metals contaminationwhen exposed to aggressive gas environments. The filter matrix of suchgas filters may be over coated with chemically inert and robust thinfilms of alumina using ALD coating techniques in accordance with thepresent disclosure. The ALD process may include any number ofdepositions cycles, e.g., in a range of from 100 to 5000 cycles. In aspecific implementation, the ALD alumina films may be deposited with 50to 1500 cycles, using a trimethylaluminum/H₂O process with extended waitand purge times, at temperature that may for example be in a range of200° C. to 300° C., e.g., 250° C., with deposition of 0.75 Å to 1.25 Åper cycle, e.g., 1.1 Å/cycle.

The ALD alumina coating process may be carried out to provide aluminacoating thicknesses on the gas filter that may for example be in a rangeof from 15 nm to 200 nm in various embodiments. In other embodiments,the ALD alumina coating thickness may be in a range of from 20 nm to 50nm.

The above-described gas filter coatings as formed by ALD coatingtechniques may be carried out to provide varying aluminum content inaluminum oxide films. For example, the aluminum content of such filmsmay be in a range of from 25 atomic percent to 40 atomic percent, invarious embodiments. In other embodiments, the aluminum content is in arange of from 28 atomic percent to 35 atomic percent, and in still otherembodiments, the aluminum content of the ALD coating is in a range offrom 30 atomic percent to 32 atomic percent of the aluminum oxide film.

In other illustrative embodiments, the gas filter may comprise anin-line metal gas filter having pore size in a range of from 2 to 5 μm,in which the filter includes a titanium filter matrix, wherein the ALDalumina coating has a thickness that may be in a range of from 10 nm to40 nm, e.g., 20 nm thickness. In still other embodiments, the gas filtermay comprise a nickel-based gas filter matrix having pore size in arange of from 2 to 5 μm, wherein the ALD alumina coating has a thicknessthat may be in a range of from 10 nm to 40 nm, e.g., 20 nm thickness.

The protective coatings of the present disclosure may also be employedfor coating of surfaces in chemical reagents supply packages, such asfluid storage and dispensing vessels, solid reagent vaporizer vessels,and the like. Such fluid storage and dispensing vessels may variouslycontain, in addition to the material to be stored in and dispensed fromsuch vessels, storage media for the stored material, from which thestored material may be disengaged for dispensing of same from the vesselof the material supply package. Such storage media may include physicaladsorbents on which fluids are reversibly adsorbed, ionic storage mediafor reversible fluid storage, and the like. For example, solid deliverypackages of the type disclosed in International PublicationWO2008/028170 published Mar. 6, 2008, the disclosure of which hereby isincorporated herein by reference in its entirety, may be coated oninterior surface thereof with a protective coating of the presentdisclosure.

Chemical reagents supply packages of other types may be employed, inwhich internal surface of a supply vessel is coated with a protectivecoating of the present disclosure, such as internally pressure-regulatedfluid supply vessels for delivery of gases, e.g., gases such as borontrifluoride, germanium tetrafluoride, silicon tetrafluoride, and othergases utilized in manufacture of semiconductor products, flat-paneldisplays, and solar panels.

A further aspect of the disclosure relates to a method of delivering agaseous or vapor stream to a semiconductor processing tool, said methodcomprising providing a flow path for the gaseous or vapor stream, from asource of said gaseous or vapor stream to the semiconductor processingtool, and flowing the gaseous or vapor stream through a filter in theflow path to remove extraneous solid material from the stream, whereinthe filter comprises a filter of a type as variously described herein.

In such method, the gaseous or vapor stream may comprise any suitablefluid species, and in particular embodiments, such stream comprisesdialuminum hexachloride. A specific filter useful for such fluidapplications includes an ALD coating comprising alumina, wherein thematrix comprises stainless steel fibers and/or particles.

The semiconductor processing tool in the aforementioned method may be ofany suitable type, and may for example comprise a vapor depositionfurnace.

As mentioned above, the filter may be varied in the ALD coating andmatrix. In specific embodiments, the filter comprises a sintered matrixof stainless steel fibers and/or particles that is coated with an ALDcoating of alumina, wherein the sintered matrix comprises pores of adiameter in a range of from 1 to 40 μm, e.g., from 1 to 20 μm, from 1 to10 μm, from 10 to 20 μm, or in other suitable range of pore diametervalues, and wherein the ALD coating in any of such embodiments has athickness in a range of from 2 to 500 nm.

The disclosure in another aspect relates to use of ALD for pore sizecontrol in fine filtration applications, to achieve filters that arespecifically tailored, beyond the capabilities afforded by sinteredmetal matrix filters alone. In this respect, control the pore sizes insintered metal matrix filters becomes progressively more difficult asthe target pore size shrinks to less than 5 μm. In accordance with thepresent disclosure, ALD coatings can be used to effectively shrink thepore size with a high degree of control of pore size and pore sizedistribution. While coatings deposited by ALD may be substantiallythicker than employed in other applications, ALD affords the possibilityof extraordinary control of the pore size and pore size distribution,while still achieving chemical resistance benefits, e.g., with ALDcoatings of alumina.

Thus, ALD coating of sintered metal matrix materials may be applied atsubstantial thicknesses on the sintered metal matrix structure, with thecoating thickness being of such magnitude as to reduce pore size in thecoated metal matrix structure to very low levels, e.g., to sub-micronpore size levels.

Such approach may also be employed to effect the creation of filterswith porosity gradients, such as a porosity gradient from a gas inletface to a gas discharge face, wherein relatively larger sized pores arepresent at the gas inlet face and relatively smaller sized pores arepresent at the gas discharge face of the filter, with a porositygradient between the respective faces of the filter. With such porositygradient, the filter may for example be employed to capture largeparticles at an entrance side of the filter and smaller particles on theexit side of the filter, so that an overall highly effective filtrationaction is achieved.

The disclosure therefore contemplates filters comprising a porousmaterial matrix coated with an ALD coating wherein the pore size of theporous metal matrix has been reduced by the ALD coating, e.g., by from5% to 95% reduction in average pore size by the ALD coating in relationto a corresponding porous material matrix not coated with the ALDcoating.

The disclosure also contemplates filters comprising a porous materialmatrix coated with an ALD coating, wherein the coating thickness isdirectionally varied to provide a corresponding pore size gradient inthe filter, e.g., from an inlet phase to an outlet face of the filter,as above described.

A further aspect of the disclosure relates to a method of fabricating aporous filter, comprising coating a porous material matrix with an ALDcoating, to reduce average pore size of the porous material matrix. Themethod may be utilized to achieve a predetermined reduction of averagepore size of the porous material matrix, and/or a directionally variedpore size gradient in the porous material matrix.

The porous material matrix in any of the above aspects and embodimentsmay comprise a sintered metal matrix, e.g., of titanium, stainlesssteel, or other metal matrix material.

In another aspect, the disclosure relates to a solid vaporizer apparatuscomprising a vessel defining an interior volume including supportsurface therein for solid material to be vaporized, wherein at least aportion of the support surface has an ALD coating thereon. The supportsurface may comprise interior surface of the vessel, such as the vesselwall surface, and/or floor of the vessel, or extended surface integrallyformed with the wall and/or floor surfaces, so that the support surfacecomprises interior surface of the vessel, and/or the support surface maycomprise surface of a support member in the interior volume, such as atrade providing support surface for the solid material to be vaporized.The tray may be coated partially or fully with the ALD coating. In otherembodiments, the vessel may contain an array of vertically spaced aparttrays, each providing support surface for the solid material. Each ofsuch trays in the array may be coated with the ALD coating.

The vessel may be fabricated with the interior wall surface of thevessel that bounds the interior volume thereof being coated with the ALDcoating. The ALD coating may for example comprise alumina, e.g., withthickness in a range of from 2 to 500 nm. The support surface coated bythe ALD coating in any of the aforementioned embodiments may be astainless steel surface. The vaporizer vessel itself may be formed ofstainless steel. The vaporizer apparatus may be provided in asolids-loaded state, containing vaporizable solid material on thesupport surface of the vessel, e.g., on support surfaces of stackedtrays in the interior volume of the vessel. The vaporizable solidmaterial may be of any suitable type, and may for example compriseprecursor material for vapor deposition or ion implantation operations.The vaporizable solid material may comprise an organometallic compound,or a metal halide compounds such as aluminum trichloride. It will beappreciated that the ALD coating applied to the support surface of thevessel may be specifically adapted to a particular vaporizable solidmaterial. It will also be appreciated that the ALD coating may beapplied to all interior surface in the interior volume of the vessel,including the wall and floor surface of the vessel as well as thesurface presented by any tray or other support structure for thevaporizable solid that is disposed in the interior volume of the vessel.

The ensuing disclosure is directed to various illustrative examples ofcoated substrate articles, devices, and apparatus of the presentdisclosure, exemplifying specific features, aspects, and characteristicsof the coating technology described herein.

Alumina coatings in accordance with the present disclosure may beapplied to surfaces of holders utilized in vaporizer ampoules such asampoules of the type shown in FIG. 3 hereof, as previously describedherein. FIG. 15 is a perspective view of a stainless steel holderusefully employed in a vaporizer ampoule for aluminum trichloride(AlCl₃) solid precursor delivery for an aluminum process, in which thealuminum trichloride precursor is supported by the holder andvolatilized to form aluminum trichloride precursor vapor for dischargefrom the vaporizer ampoule and transport through associated flowcircuitry to the aluminum process. The aluminum process may for examplebe employed for metallization of a semiconductor device structure onand/or in a suitable wafer substrate.

FIG. 16 is a perspective view of a stainless steel holder of the typeshown in FIG. 15, as coated by atomic layer deposition with a coating ofalumina thereon, so that the stainless steel surface is encapsulated bythe alumina coating in the corrosive environment involving aluminumtrichloride (AlCl₃) exposure to which the holder is subjected in use andoperation of the vaporizer ampoule. By such alumina coating, the holderis protected against corrosion, and metals contamination of theprecursor vapor is substantially reduced. In addition to such aluminacoating of the holder, the entire interior surface of the vaporizerampoule may likewise be coated, as well as exterior surfaces of theampoule, to provide extended protection against the corrosiveenvironment deriving from the processing of the aluminum trichloride(AlCl₃) solid precursor to volatilize same for generation of precursorvapor for the aluminum process, or for other usage.

The alumina coating on the surface of the holder and/or other vaporizerampoule services may be of any suitable thickness, and may for examplebe in a thickness range of from 20 nm to 250 nm or more. In variousembodiments, the coating thickness on the holder surfaces may be in arange of from 50 to 125 nm. It will be appreciated that any suitablethickness of the alumina coating may be applied by carrying out thecorresponding vapor deposition operation for a corresponding number ofdeposition cycles and deposition times, with a suitable thickness beingdeterminable by empirical methods as appropriate to provide a desiredlevel of anti-corrosion protection to the metal surface.

FIG. 17 is a schematic elevation view of the alumina coating applied byatomic layer deposition to the stainless steel substrate, as describedabove in application to the solid precursor holder utilized in thevaporizer ampoule. The alumina coating provides corrosion resistance,prevents chemical reaction with the substrate, and reduces metalscontamination in use of the vaporizer for aluminum trichloride precursorvapor generation.

In another application, yttria coatings may be applied to surfaces ofetching apparatus or apparatus components, e.g., surfaces of injectornozzles used in plasma etch equipment. FIG. 18 shows channels of aplasma etch apparatus coated with yttria (Y₂O₃). Yttria provides an etchresistant coating that is suitable for surfaces and parts of complicatedshape, such as high aspect ratio features. When deposited by atomiclayer deposition, yttria forms a dense, conformal, pin-hole free coatingthat is resistant to etching, and provides substantially reducedparticle shedding and erosion in relation to surfaces lacking suchyttria coating.

Yttria coatings may be applied by atomic layer deposition over alumina,as in the schematic elevation view of FIG. 19. In application to plasmaetching equipment and equipment components, the ALD yttria layerprovides enhanced corrosion-resistance and etch-resistance, protectingthe underlying surface against deleterious plasma exposure, such asexposure to chloro- and fluoro- and other halogen-based plasmas. The ALDyttria layer thereby reduces generation of unwanted particles, andincreases the lifetime of parts of the plasma etching equipment whosesurfaces are coated with the yttria coating.

In another application, load lock components employed for etch chamberapparatus are exposed in use to residual etch chemistries from the etchchamber, resulting in severe corrosion of metal components. An exampleis a diffuser plate, which may be constructed of stainless steel orother metal or metal alloy, with a filter membrane, formed for exampleof nickel or other metal or metal alloy. Such diffuser plate assemblymay be coated with an alumina coating to encapsulate and protect thediffuser plate and filter membrane. By complete encapsulation of thefilter membrane, corrosion of the membrane is prevented.

FIG. 20 is a photograph of a diffuser plate assembly, including astainless steel frame and a nickel filter membrane, as coated with analumina coating. FIG. 21 is a schematic elevation view of the diffuserplate assembly, in which the stainless steel frame and nickel membraneare encapsulated with ALD alumina. The ALD coating provides a corrosionresistant and etch resistant layer that protects against deleteriouschemistries, e.g., hydrogen bromide-based chemistries, reducingparticles, and increasing the lifetime of the assembly.

Another application relates to semiconductor process equipment that isexposed to chlorine-based precursors from ALD processing, and tofluorine-based plasmas from chamber cleaning operations. In suchapplications, yttria coatings may be employed to provide good etchresistance and to coat parts with complicated shapes. One approach insuch applications is the use of a combination of physical vapordeposition (PVD) and atomic layer deposition (ALD) of yttria, with ALDbeing employed for thinner coating of high aspect ratio features andcritical elements, and thicker coating of PVD for the remainder of thepart. In such application, the yttria ALD layer providescorrosion-resistance and etch-resistance, protection againstfluorine-based chemistries and fluorine-based plasmas, reducing particlegeneration and increasing lifetime of parts that are coated with theprotective yttria coating.

A further application relates to coating of quartz envelopes structures,such as bulbs of ultraviolet (UV) curing lamps that are used in back endof line (BEOL) and front end of line (FEOL) UV curing operations. In theoperation of UV lamps, such as those in which the bulb is fabricated ofquartz, mercury will diffuse into the quartz during operation at thehigh temperatures involved, e.g., on the order of 1000° C., and suchmercury diffusion will result in degradation of the UV lamp andsubstantial shortening of its operational service life. To combat suchmercury migration into the quartz envelope (bulb) material, aluminaand/or yttria is coated on the interior surface of the bulb to provide adiffusion barrier layer against incursion of mercury into the quartzenvelope material.

More generally, alumina coatings may be employed to overcoat andencapsulate metal components of various types, to impart corrosionresistance, prevent chemical reaction with the substrate, and to reducemetals contamination, so that operating service life of components, suchas gas lines, valves, tubes, housings, and the like, are correspondinglyextended. By use of atomic layer deposition, interior surfaces of partscan be coated, including parts with complex interior surface geometry,and layers of alumina or other protective coatings may be employed toprovide dense, pin-hole free and conformal protective layers over thesubstrate surface.

Another application of protective coatings of the present disclosure isthe protective coating of plasma source surfaces, such as are used insemiconductor manufacturing, and manufacture of flat-panel displays, aswell as solar panel manufacturing. Such plasma sources may be of anysuitable type, and may for example generate ammonia plasmas, hydrogenplasmas, nitrogen trifluoride plasmas, and plasmas of other varieties.The protective coatings can be utilized in place of anodizing surfacesof plasma-wetted parts, to provide enhanced plasma etch resistance,e.g., greater than 1000 hours exposure to NF₃ plasma, whileaccommodating hydrogen (H*) and fluorine (F*) surface recombination, andhigh electrical standoff voltages, e.g., greater than 1000 V.

An example plasma source apparatus may be formed of aluminum, or analuminum compound such as aluminum oxynitride, in which a plasma channeland a water channel of the apparatus are coated with coatings. Theplasma channel coating and the water channel coating may comprise an ALDcoating of alumina, over which is deposited a physical vapor deposition(PVD) coating of aluminum oxynitride (AlON), as shown in the schematicelevation view of FIG. 22, showing the aluminum substrate, the ALDcoating of alumina, and the PVD coating of AlON. The thicknesses of therespective alumina and aluminum oxynitride coatings may be of anysuitable thickness. By way of example, the thickness of the aluminacoating may be in a range of from 0.05 to 5 μm, and the thickness of thePVD coating may be in a range of from 2 to 25 μm. In a specificembodiment, the alumina coating has a thickness of 1 μm, and the PVDAlON coating has a thickness of 10 μm. In the structure, the PVD AlONcoating provides the apparatus with etch resistance and plasma surfacerecombination capability, and the alumina coating, in addition toproviding etch resistance provides an electrical standoff coating.

A further application relates to dielectric stacks for hot chuckcomponents, which may have a layer structure as shown in FIG. 23. Asshown, an alumina substrate has an electrode metal, e.g., nickel,thereon, on which is an electrical stand-off layer of ALD alumina.Deposited on the alumina layer is a PVD coating of aluminum oxynitride,and deposited on the AlON layer is a layer of chemical vapor deposition(CVD) deposited silicon oxynitride (SiON). In this layer structure, theCVD SiON layer provides a clean way for contact surface and electricalspacer, the PVD AlON layer provides a coefficient of thermal expansion(CTE) buffer layer, the ALD layer of alumina provides an electricalstand-off layer, and the nickel provides an electrode metal layer, onthe alumina substrate.

A still further application relates to plasma activation chuckcomponents of plasma activation chambers, in which aluminum parts arecoated with a multilayer stack including the multilayer stacks shown inFIGS. 24 and 25. The multilayer stack of FIG. 24 includes a chemicalvapor deposition-applied layer of silicon on the aluminum substrate,with an ALD layer of zirconia on the CVD Si layer. In this multilayerstack, the ALD layer of zirconia functions to provide a clean, dense wayfor contact surface, serving as a diffusion barrier layer, and anelectrical standoff. The CVD silicon layer provides a clean buffer layeron the aluminum substrate. The multilayer stack of FIG. 25 includes aCVD layer of silicon oxynitride on the aluminum substrate, and an ALDlayer of alumina on the CVD SiON coating layer, wherein the ALD aluminalayer functions as an electrical stand-off layer, a diffusion barrierlayer, and a layer providing a clean, dense way for contact surface. TheCVD SiON layer provides a clean buffer layer in the multilayer coatingstructure.

A further application of the coating technology of the presentdisclosure relates to coating of porous matrix and filter articles, inwhich coatings such as alumina may be deposited by atomic layerdeposition, which enables independent control of penetration depth andcoating thickness in the porous matrix or filter material. Eitherpartial alumina coating penetration or full alumina coating penetrationmay be employed, depending on the article and its specific end use.

FIG. 26 is a micrograph of porous material having a 1.5 mm wallthickness and pore size of 2-4 μm, coated with alumina by atomic layerdeposition. FIG. 27 is a schematic representation of an encapsulatedmembrane, comprising a membrane formed of stainless steel, nickel,titanium, or other suitable material, which has been fully encapsulatedwith alumina deposited by ALD, to provide the encapsulated membrane withcorrosion resistance and etch resistance, protection against chemicalattack, reduction of particle generation, and reduction of metalscontamination.

The use of atomic layer deposition, as indicated, provides an ability toindependently control coating penetration depth and coating thickness.This ability is usefully employed to control pore size and flowrestriction of ultra-fine membranes, such as for example those withnominal pore size in a range of from 20 nm to 250 nm, e.g., a nominalpore size on the order of 100 nm.

FIG. 28 is a photomicrograph of a coated filter, wherein the coating isalumina, having a coating penetration depth of 35 μm. FIG. 29 is aphotomicrograph of a coated filter, wherein the coating is alumina,having a coating penetration depth of 175 μm.

Consistent with the preceding disclosure herein, the present disclosurerelates in one aspect to a solid vaporizer apparatus comprising acontainer defining therein an interior volume, an outlet configured todischarge precursor vapor from the container, and support structure inthe interior volume of the container adapted to support solid precursormaterial thereon for volatilization thereof to form the precursor vapor,wherein the solid precursor material comprises aluminium precursor, andwherein at least part of surface area in the interior volume is coatedwith an alumina coating. In various embodiments of such solid vaporapparatus, the surface area may comprise at least one of surface area ofthe support structure, and surface area of the container in saidinterior volume. In other embodiments, the surface area may comprisesurface area of the support structure, and surface area of the containerin said interior volume. In still other embodiments, the surface area inthe interior volume that is coated with an alumina coating, comprisesstainless steel. In various implementations of the solid vaporizerapparatus, the alumina coating may have thickness in a range of from 20to 125 nm, the alumina coating may for example comprise an ALD aluminacoating in any of the foregoing aspects and embodiments.

The disclosure in another aspect relates to a method of enhancingcorrosion resistance of a stainless steel structure, material, orapparatus that in use or operation is exposed to aluminum halide, saidmethod comprising coating said stainless steel structure, material, orapparatus with an alumina coating. The alumina coating in such methodmay for example have thickness in a range of from 20 to 125 nm. Thealumina coating may for example be applied by atomic layer deposition.

In a further aspect, the disclosure relates to a semiconductorprocessing etching structure, component, or apparatus that in use oroperation is exposed to etching media, said structure, component, orapparatus being coated with a coating comprising a layer of yttria,wherein the layer of yttria optionally overlies a layer of alumina insaid coating. The etching structure, component, or apparatus may forexample comprise an etching apparatus injector nozzle.

Another aspect of the disclosure relates to a method of enhancingcorrosion resistance and etch resistance of a semiconductor processingetching structure, component, or apparatus that in use or operation isexposed to etching media, said method comprising coating the structure,component, or apparatus with a coating comprising a layer of yttria,wherein the layer of yttria optionally overlies a layer of alumina insaid coating.

Still another aspect of the disclosure relates to an etch chamberdiffuser plate comprising a nickel membrane encapsulated with an aluminacoating. In such etch chamber diffuser plate, the alumina coating maycomprise an ALD alumina coating.

A further aspect of the disclosure relates to a method of enhancingcorrosion resistance and etch resistance of an etch chamber diffuserplate comprising a nickel membrane, comprising coating the nickelmembrane with an encapsulating coating of alumina. The coating ofalumina may for example comprise an ALD coating.

The disclosure in another aspect relates to a vapor depositionprocessing structure, component, or apparatus that in use or operationis exposed to halide media, said structure, component, or apparatusbeing coated with a coating of yttria comprising an ALD base coating ofyttria, and a PVD overcoming of yttria. In such structure, component, orapparatus, the surface that is coated with the ALD base coating ofyttria, and the PVD overcoating of yttria, may comprise aluminum.

A further aspect of the disclosure relates to a method of enhancingcorrosion resistance and etch resistance of a vapor depositionprocessing structure, component, or apparatus that in use or operationis exposed to halide media, said method comprising coating thestructure, component, or apparatus with a coating of yttria comprisingan ALD base coating of yttria, and a PVD over coating of yttria. Asnoted above, the structure, component, or apparatus may comprisealuminum surface that is coated with the coating of yttria.

Another aspect the disclosure relates to a quartz envelope structurecoated on an interior surface thereof with an alumina diffusion barrierlayer.

A corresponding aspect of the disclosure relates to a method of reducingdiffusion of mercury into a quartz envelope structure susceptible tosuch diffusion in operation thereof, said method comprising coating aninterior surface of the quartz envelope structure with an aluminadiffusion barrier layer.

The disclosure in a further aspect relates to a plasma source structure,component, or apparatus that in use or operation is exposed to plasmaand voltage exceeding 1000 V, wherein plasma-wetted surface of saidstructure, component or apparatus is coated with an ALD coating ofalumina, and said alumina coating is overcoated with a PVD coating ofaluminum oxynitride. The plasma-wetted surface may for example comprisealuminum or aluminum oxynitride.

A further aspect of the disclosure relates to a method of enhancingservice life of a plasma source structure, component, or apparatus thatin use or operation is exposed to plasma and voltage exceeding 1000 V,said method comprising coating plasma-wetted surface of said structure,component or apparatus with an ALD coating of alumina, and over coatingsaid alumina coating with a PVD coating of aluminum oxynitride. Asindicated above, the plasma-wetted surface may comprise aluminum oraluminum oxynitride.

An additional aspect of the disclosure relates to a dielectric stack,comprising sequential layers including a base layer of alumina, a nickelelectrode layer thereon, an ALD alumina electrical stand-off layer onthe nickel electrode layer, a PVD aluminum oxynitride thermal expansionbuffer layer on the ALD alumina electrical stand-off layer, and a CVDsilicon oxynitride wafer contact surface and electrical spacer layer onthe PVD aluminum oxynitride thermal expansion buffer layer.

A plasma activation structure, component, or apparatus is contemplatedin another aspect of the disclosure, comprising aluminum surface coatedwith one of the multilayer coatings of (i) and (ii): (i) a base coat ofCVD silicon on the aluminum surface, and a layer of ALD zirconia on thebase coat of CVD silicon; and (ii) a base coat of CVD silicon oxynitrideon the aluminum surface, and a layer of ALD alumina on the base coat ofCVD silicon oxynitride.

A corresponding method is contemplated for reducing particle formationand metal contamination for an aluminum surface of a plasma activationstructure, component, or apparatus, said method comprising coating thealuminum surface with one of the multilayer coatings of (i) and (ii):(i) a base coat of CVD silicon on the aluminum surface, and a layer ofALD zirconia on the base coat of CVD silicon; and (ii) a base coat ofCVD silicon oxynitride on the aluminum surface, and a layer of ALDalumina on the base coat of CVD silicon oxynitride.

The disclosure contemplates, in another aspect, a porous matrix filtercomprising a membrane formed of stainless steel, nickel, or titanium,wherein the membrane is encapsulated with alumina to a coatingpenetration depth in a range of from 20 to 2000 μm. More specifically,in various embodiments, the porosity may have nominal pore size in arange of from 10 to 1000 nm.

Another aspect of the disclosure relates to a method of making a porousmatrix filter comprising encapsulating a membrane formed of stainlesssteel, nickel, or titanium with alumina to a coating penetration depthin a range of from 20 to 2000 μm. in a specific embodiment of suchmethod, the encapsulating comprises ALD of the alumina, and the methodis conducted to provide porosity in the porous matrix filter havingnominal pore size in a range of from 10 to 1000 nm.

While the disclosure has been set forth herein in reference to specificaspects, features and illustrative embodiments, it will be appreciatedthat the utility of the disclosure is not thus limited, but ratherextends to and encompasses numerous other variations, modifications andalternative embodiments, as will suggest themselves to those of ordinaryskill in the field of the present disclosure, based on the descriptionherein. Correspondingly, the disclosure as hereinafter claimed isintended to be broadly construed and interpreted, as including all suchvariations, modifications and alternative embodiments, within its spiritand scope.

1-134. (canceled)
 135. A porous matrix filter comprising a metalmembrane, wherein the metal membrane is encapsulated with a metal oxidecoating having a penetration depth in a range of from 20 to 2000 μm.136. The porous matrix filter of claim 135, wherein the metal membraneis formed of stainless steel, nickel, or titanium.
 137. The porousmatrix filter of claim 135, wherein the metal membrane is a sinteredmatrix of stainless steel fibers, particles, or both.
 138. The porousmatrix filter of claim 135, wherein the metal oxide coating comprises ametal oxide selected from the group consisting of titania, alumina,zirconia, oxides of the formula MO wherein M is Ca, Mg, or Be, oxides ofthe formula M′O2, wherein M′ is a stoichiometrically acceptable metal,and oxides of the formula Ln2O3 wherein Ln is a lanthanide element, La,Sc, or Y.
 139. The porous matrix filter of claim 135, wherein the metaloxide coating is an alumina coating.
 140. The porous matrix filter ofclaim 135, wherein the metal oxide coating is an ALD coating having athickness in a range of from 2 to 500 nm.
 141. The porous matrix filterof claim 6, wherein the thickness is in a range of from 15-200 nm. 142.The porous matrix filter of claim 140, wherein the thickness is in arange of from 20-50 nm.
 143. The porous matrix filter of claim 135,wherein the metal oxide coating is an ALD coating having a thicknessthat is directionally varied to provide a corresponding pore sizegradient within the porous matrix filter.
 144. The porous matrix filterof claim 135, wherein the metal oxide coating has a penetration depth ina range of from 20 to 250 μm.
 145. The porous matrix filter of claim135, wherein the porous matrix filter has porosity having a nominal poresize in a range of from 10 to 1000 nm.
 146. A filter comprising a matrixof metal fibers, metal particles, or both metal fibers and metalparticles having an ALD coating thereon, wherein the ALD coating doesnot alter pore volume of the matrix of metal fibers, metal particles, orboth metal fibers and metal particles by more than 5%, as compared to acorresponding matrix of metal fibers, metal particles, or both metalfibers and metal particles lacking the ALD coating thereon, and whereinthe matrix is characterized by pores of diameter in a range of from 1 to40 μm.
 147. The filter of claim 146, wherein the filter is contained ina housing.
 148. A method of making a porous matrix filter comprisingencapsulating a metal membrane with a metal oxide coating by ALD to apenetration depth in a range of from 20 to 2000 μm.
 149. The method ofclaim 148, wherein the metal membrane is formed of stainless steel,nickel, or titanium.
 150. The method of claim 148, wherein the metalmembrane is a sintered matrix of stainless steel fibers, particles, orboth.
 151. The method of claim 148, wherein the metal oxide coatingcomprises a metal oxide selected from the group consisting of titania,alumina, zirconia, oxides of the formula MO wherein M is Ca, Mg, or Be,oxides of the formula M′O2, wherein M′ is a stoichiometricallyacceptable metal, and oxides of the formula Ln2O3 wherein Ln is alanthanide element, La, Sc, or Y.
 152. The method of claim 148, whereinthe metal oxide coating is an alumina coating.
 153. The method of claim148, wherein the porous matrix filter has an average pore size that hasbeen reduced by the ALD coating by from 5% to 95% in relation to acorresponding porous matrix filter not coated with the ALD coating. 154.The method of claim 148, wherein the coating thickness is directionallyvaried to provide a corresponding pore size gradient in the filter.